diff --git a/README.md b/README.md
index 6699da0..3cb9603 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # Twine
 
-Twine is a command line tool for managing your strings and their translations. These strings are all stored in a master text file and then Twine uses this file to import and export strings in a variety of file types, including iOS and Mac OS X `.strings` files, Android `.xml` files, gettext `.po` files, and [jquery-localize][jquerylocalize] `.json` files. This allows individuals and companies to easily share strings across multiple projects, as well as export strings in any format the user wants.
+Twine is a command line tool for managing your strings and their translations. These are all stored in a master text file and then Twine uses this file to import and export localization files in a variety of types, including iOS and Mac OS X `.strings` files, Android `.xml` files, gettext `.po` files, and [jquery-localize][jquerylocalize] `.json` files. This allows individuals and companies to easily share translations across multiple projects, as well as export localization files in any format the user wants.
 
 ## Install
 
@@ -21,19 +21,19 @@ You can also run Twine directly from source. However, it requires [rubyzip][ruby
 
 Make sure you run the `twine` executable at the root of the project as it properly sets up your Ruby library path. The `bin/twine` executable does not.
 
-## String File Format
+## Twine File Format
 
-Twine stores all of its strings in a single file. The format of this file is a slight variant of the [Git][git] config file format, which itself is based on the old [Windows INI file][INI] format. The entire file is broken up into sections, which are created by placing the section name between two pairs of square brackets. Sections are optional, but they are a recommended way of breaking your strings into smaller, more manageable chunks.
+Twine stores everything in a single file, the Twine data file. The format of this file is a slight variant of the [Git][git] config file format, which itself is based on the old [Windows INI file][INI] format. The entire file is broken up into sections, which are created by placing the section name between two pairs of square brackets. Sections are optional, but they are the recommended way of grouping your definitions into smaller, more manageable chunks.
 
-Each grouping section contains N string definitions. These string definitions start with the string key placed within a single pair of square brackets. This string definition then contains a number of key-value pairs, including a comment, a comma-separated list of tags (which are used by Twine to select a subset of strings), and all of the translations.
+Each grouping section contains N definitions. These definitions start with the key placed within a single pair of square brackets. It then contains a number of key-value pairs, including a comment, a comma-separated list of tags and all of the translations.
 
 ### Placeholders
 
-Twine supports [`printf` style placeholders](https://en.wikipedia.org/wiki/Printf_format_string) with one peculiarity: `@` is used for strings instead of `s`. This is because Twine started out as a tool for iOS and OS X projects.
+Twine supports [`printf` style placeholders][printf] with one peculiarity: `@` is used for strings instead of `s`. This is because Twine started out as a tool for iOS and OS X projects.
 
 ### Tags
 
-Tags are used by Twine as a way to only work with a subset of your strings at any given point in time. Each string can be assigned zero or more tags which are separated by commas. Tags are optional, though highly recommended. You can get a list of all strings currently missing tags by executing the `validate-strings-file` command.
+Tags are used by Twine as a way to only work with a subset of your definitions at any given point in time. Each definition can be assigned zero or more tags which are separated by commas. Tags are optional, though highly recommended. You can get a list of all definitions currently missing tags by executing the [`validate-twine-file`](#validate-twine-file) command.
 
 ### Whitespace
 
@@ -41,7 +41,7 @@ Whitepace in this file is mostly ignored. If you absolutely need to put spaces a
 
 ### References
 
-If you want a key to inherit the values of another key, you can use a reference. Any property not specified for a key will be taken from the reference.
+If you want a definition to inherit the values of another definition, you can use a reference. Any property not specified for a definition will be taken from the reference.
 
 ### Example
 
@@ -83,7 +83,7 @@ If you want a key to inherit the values of another key, you can use a reference.
 
 ## Supported Output Formats
 
-Twine currently supports the following formats for outputting strings:
+Twine currently supports the following output formats:
 
 * [iOS and OS X String Resources][applestrings] (format: apple)
 * [Android String Resources][androidstrings] (format: android)
@@ -92,67 +92,67 @@ Twine currently supports the following formats for outputting strings:
 * [Django PO Files][djangopo] (format: django)
 * [Tizen String Resources][tizen] (format: tizen)
 
-If you would like to enable twine to create language files in another format, create an appropriate formatter in `lib/twine/formatters`.
+If you would like to enable Twine to create localization files in another format, read the wiki page on how to create an appropriate formatter.
 
 ## Usage
 
-	Usage: twine COMMAND STRINGS_FILE [INPUT_OR_OUTPUT_PATH] [--lang LANG1,LANG2...] [--tags TAG1,TAG2,TAG3...] [--format FORMAT]
+	Usage: twine COMMAND TWINE_FILE [INPUT_OR_OUTPUT_PATH] [--lang LANG1,LANG2...] [--tags TAG1,TAG2,TAG3...] [--format FORMAT]
 
 ### Commands
 
-#### `generate-string-file`
+#### `generate-localization-file`
 
-This command creates an Apple or Android strings file from the master strings data file. If the output file would not contain any translations, twine will exit with an error.
+This command creates a localization file from the Twine data file. If the output file would not contain any translations, Twine will exit with an error.
 
-	$ twine generate-string-file /path/to/strings.txt values-ja.xml --tags common,app1
-	$ twine generate-string-file /path/to/strings.txt Localizable.strings --lang ja --tags mytag
-	$ twine generate-string-file /path/to/strings.txt all-english.strings --lang en
+	$ twine generate-localization-file /path/to/twine.txt values-ja.xml --tags common,app1
+	$ twine generate-localization-file /path/to/twine.txt Localizable.strings --lang ja --tags mytag
+	$ twine generate-localization-file /path/to/twine.txt all-english.strings --lang en
 
-#### `generate-all-string-files`
+#### `generate-all-localization-files`
 
-This command is a convenient way to call `generate-string-file` multiple times. It uses standard Mac OS X, iOS, and Android conventions to figure out exactly which files to create given a parent directory. For example, if you point it to a parent directory containing `en.lproj`, `fr.lproj`, and `ja.lproj` subdirectories, Twine will create a `Localizable.strings` file of the appropriate language in each of them. However, files that would not contain any translations will not be created; instead warnings will be logged to `stderr`. This is often the command you will want to execute during the build phase of your project.
+This command is a convenient way to call [`generate-localization-file`](#generate-localization-file) multiple times. It uses standard conventions to figure out exactly which files to create given a parent directory. For example, if you point it to a parent directory containing `en.lproj`, `fr.lproj`, and `ja.lproj` subdirectories, Twine will create a `Localizable.strings` file of the appropriate language in each of them. However, files that would not contain any translations will not be created; instead warnings will be logged to `stderr`. This is often the command you will want to execute during the build phase of your project.
 
-	$ twine generate-all-string-files /path/to/strings.txt /path/to/project/locales/directory --tags common,app1
+	$ twine generate-all-localization-files /path/to/twine.txt /path/to/project/locales/directory --tags common,app1
 
-#### `consume-string-file`
+#### `consume-localization-file`
 
-This command slurps all of the strings from a `.strings` or `.xml` file and incorporates the translated text into the master strings data file. This is a simple way to incorporate any changes made to a single file by one of your translators. It will only identify strings that already exist in the master data file.
+This command slurps all of the translations from a localization file and incorporates the translated strings into the Twine data file. This is a simple way to incorporate any changes made to a single file by one of your translators. It will only identify definitions that already exist in the data file.
 
-	$ twine consume-string-file /path/to/strings.txt fr.strings
-	$ twine consume-string-file /path/to/strings.txt Localizable.strings --lang ja
-	$ twine consume-string-file /path/to/strings.txt es.xml
+	$ twine consume-localization-file /path/to/twine.txt fr.strings
+	$ twine consume-localization-file /path/to/twine.txt Localizable.strings --lang ja
+	$ twine consume-localization-file /path/to/twine.txt es.xml
 
-#### `consume-all-string-files`
+#### `consume-all-localization-files`
 
-This command reads in a folder containing many `.strings` or `.xml` files. These files should be in a standard folder hierarchy so that twine knows the language of each file. When combined with the `--developer-language`, `--consume-comments`, and `--consume-all` flags, this command is a great way to create your initial strings data file from an existing iOS or Android project. Just make sure that you create a blank strings.txt file, first!
+This command reads in a folder containing many localization files. These files should be in a standard folder hierarchy so that Twine knows the language of each file. When combined with the `--developer-language`, `--consume-comments`, and `--consume-all` flags, this command is a great way to create your initial Twine data file from an existing project. Just make sure that you create a blank Twine data file first!
 
-	$ twine consume-all-string-files strings.txt Resources/Locales --developer-language en --consume-all --consume-comments
+	$ twine consume-all-localization-files twine.txt Resources/Locales --developer-language en --consume-all --consume-comments
 
 #### `generate-loc-drop`
 
-This command is a convenient way to generate a zip file containing files created by the `generate-string-file` command. If a file would not contain any translated strings, it is skipped and a warning is logged to `stderr`. This command can be used to create a single zip containing a large number of strings in all languages which you can then hand off to your translation team.
+This command is a convenient way to generate a zip file containing files created by the [`generate-localization-file`](#generate-localization-file) command. If a file would not contain any translated strings, it is skipped and a warning is logged to `stderr`. This command can be used to create a single zip containing a large number of translations in all languages which you can then hand off to your translation team.
 
-	$ twine generate-loc-drop /path/to/strings.txt LocDrop1.zip
-	$ twine generate-loc-drop /path/to/strings.txt LocDrop2.zip --lang en,fr,ja,ko --tags common,app1
+	$ twine generate-loc-drop /path/to/twine.txt LocDrop1.zip
+	$ twine generate-loc-drop /path/to/twine.txt LocDrop2.zip --lang en,fr,ja,ko --tags common,app1
 
 #### `consume-loc-drop`
 
-This command is a convenient way of taking a zip file and executing the `consume-string-file` command on each file within the archive. It is most often used to incorporate all of the changes made by the translation team after they have completed work on a localization drop.
+This command is a convenient way of taking a zip file and executing the [`consume-localization-file`](#consume-localization-file) command on each file within the archive. It is most often used to incorporate all of the changes made by the translation team after they have completed work on a localization drop.
 
-	$ twine consume-loc-drop /path/to/strings.txt LocDrop2.zip
+	$ twine consume-loc-drop /path/to/twine.txt LocDrop2.zip
 
-#### `validate-strings-file`
+#### `validate-twine-file`
 
-This command validates that the strings file can be parsed, contains no duplicate keys, and that all strings have at least one tag. It will exit with a non-zero status code if any of those criteria are not met.
+This command validates that the Twine data file can be parsed, contains no duplicate keys, and that no key contains invalid characters. It will exit with a non-zero status code if any of those criteria are not met.
 
-	$ twine validate-strings-file /path/to/strings.txt
+	$ twine validate-twine-file /path/to/twine.txt
 
-## Creating Your First strings.txt File
+## Creating Your First Twine Data File
 
-The easiest way to create your first strings.txt file is to run the `consume-all-string-files` command. The one caveat is to first create a blank strings.txt file to use as your starting point. Then, just point the `consume-all-string-files` command at a directory in your project containing all of your iOS, OS X, or Android strings files.
+The easiest way to create your first Twine data file is to run the [`consume-all-localization-files`](#consume-all-localization-files) command. The one caveat is to first create a blank file to use as your starting point. Then, just point the `consume-all-localization-files` command at a directory in your project containing all of your localization files.
 
-	$ touch strings.txt
-	$ twine consume-all-string-files strings.txt Resources/Locales --developer-language en --consume-all --consume-comments
+	$ touch twine.txt
+	$ twine consume-all-localization-files twine.txt Resources/Locales --developer-language en --consume-all --consume-comments
 
 ## Twine and Your Build Process
 
@@ -161,12 +161,12 @@ The easiest way to create your first strings.txt file is to run the `consume-all
 It is easy to incorporate Twine right into your iOS and OS X app build processes.
 
 1. In your project folder, create all of the `.lproj` directories that you need. It does not really matter where they are. We tend to put them in `Resources/Locales/`.
-2. Run the `generate-all-string-files` command to create all of the string files you need in these directories. For example,
+2. Run the [`generate-all-localization-files`](#generate-all-localization-files) command to create all of the `.strings` files you need in these directories. For example,
 
-		$ twine generate-all-string-files strings.txt Resources/Locales/ --tags tag1,tag2
+		$ twine generate-all-localization-files twine.txt Resources/Locales/ --tags tag1,tag2
 
-	Make sure you point Twine at your strings data file, the directory that contains all of your `.lproj` directories, and the tags that describe the strings you want to use for this project.
-3. Drag the `Resources/Locales/` directory to the Xcode project navigator so that Xcode knows to include all of these strings files in your build.
+	Make sure you point Twine at your data file, the directory that contains all of your `.lproj` directories, and the tags that describe the definitions you want to use for this project.
+3. Drag the `Resources/Locales/` directory to the Xcode project navigator so that Xcode knows to include all of these `.strings` files in your build.
 4. In Xcode, navigate to the "Build Phases" tab of your target.
 5. Click on the "Add Build Phase" button and select "Add Run Script".
 6. Drag the new "Run Script" build phase up so that it runs earlier in the build process. It doesn't really matter where, as long as it happens before the resources are copied to your bundle.
@@ -178,8 +178,8 @@ Now, whenever you build your application, Xcode will automatically invoke Twine
 
 Add the following task at the top level in app/build.gradle:
 ```
-task generateStrings {
-    String script = 'if hash twine 2>/dev/null; then twine generate-string-file strings.txt ./src/main/res/values/generated_strings.xml; fi'
+task generateLocalizations {
+    String script = 'if hash twine 2>/dev/null; then twine generate-localization-file twine.txt ./src/main/res/values/generated_strings.xml; fi'
     exec {
         executable "sh"
         args '-c', script
@@ -187,12 +187,12 @@ task generateStrings {
 }
 ```
 
-Now every time you build your app the strings are generated from the twine file.
+Now every time you build your app the localization files are generated from the Twine file.
 
 
 ## User Interface
 
-* [Twine TextMate 2 Bundle](https://github.com/mobiata/twine.tmbundle) — This [TextMate 2](https://github.com/textmate/textmate) bundle will make it easier for you to work with Twine strings files. In particular, it lets you use code folding to easily collapse and expand both strings and sections.
+* [Twine TextMate 2 Bundle](https://github.com/mobiata/twine.tmbundle) — This [TextMate 2](https://github.com/textmate/textmate) bundle will make it easier for you to work with Twine files. In particular, it lets you use code folding to easily collapse and expand both definitions and sections.
 * [twine_ui](https://github.com/Daij-Djan/twine_ui) — A user interface for Twine written by [Dominik Pich](https://github.com/Daij-Djan/). Consider using this if you would prefer to use Twine without dropping to a command line.
 
 ## Plugin Support
@@ -229,7 +229,7 @@ Many thanks to all of the contributors to the Twine project, including:
 * [Kevin Wood](https://github.com/kwood)
 * [Mohammad Hejazi](https://github.com/MohammadHejazi)
 * [Robert Guo](http://www.robertguo.me/)
-* [sebastianludwig](https://github.com/sebastianludwig)
+* [Sebastian Ludwig](https://github.com/sebastianludwig)
 * [Sergey Pisarchik](https://github.com/SergeyPisarchik)
 * [Shai Shamir](https://github.com/pichirichi)
 
@@ -243,3 +243,4 @@ Many thanks to all of the contributors to the Twine project, including:
 [jquerylocalize]: https://github.com/coderifous/jquery-localize
 [djangopo]: https://docs.djangoproject.com/en/dev/topics/i18n/translation/
 [tizen]: https://developer.tizen.org/documentation/articles/localization
+[printf]: https://en.wikipedia.org/wiki/Printf_format_string
diff --git a/lib/twine.rb b/lib/twine.rb
index ff5621c..633de5c 100644
--- a/lib/twine.rb
+++ b/lib/twine.rb
@@ -23,7 +23,7 @@ module Twine
 
   require 'twine/plugin'
   require 'twine/cli'
-  require 'twine/stringsfile'
+  require 'twine/twine_file'
   require 'twine/encoding'
   require 'twine/output_processor'
   require 'twine/placeholders'
diff --git a/lib/twine/cli.rb b/lib/twine/cli.rb
index 9705a06..295922d 100644
--- a/lib/twine/cli.rb
+++ b/lib/twine/cli.rb
@@ -3,57 +3,57 @@ require 'optparse'
 module Twine
   module CLI
     NEEDED_COMMAND_ARGUMENTS = {
-      'generate-string-file' => 3,
-      'generate-all-string-files' => 3,
-      'consume-string-file' => 3,
-      'consume-all-string-files' => 3,
+      'generate-localization-file' => 3,
+      'generate-all-localization-files' => 3,
+      'consume-localization-file' => 3,
+      'consume-all-localization-files' => 3,
       'generate-loc-drop' => 3,
       'consume-loc-drop' => 3,
-      'validate-strings-file' => 2
+      'validate-twine-file' => 2
     }
 
     def self.parse(args)
       options = { include: :all }
 
       parser = OptionParser.new do |opts|
-        opts.banner = 'Usage: twine COMMAND STRINGS_FILE [INPUT_OR_OUTPUT_PATH] [--lang LANG1,LANG2...] [--tags TAG1,TAG2,TAG3...] [--format FORMAT]'
+        opts.banner = 'Usage: twine COMMAND TWINE_FILE [INPUT_OR_OUTPUT_PATH] [--lang LANG1,LANG2...] [--tags TAG1,TAG2,TAG3...] [--format FORMAT]'
         opts.separator ''
-        opts.separator 'The purpose of this script is to convert back and forth between multiple data formats, allowing us to treat our strings (and translations) as data stored in a text file. We can then use the data file to create drops for the localization team, consume similar drops returned by the localization team, and create formatted string files to ship with your products.'
+        opts.separator 'The purpose of this script is to convert back and forth between multiple data formats, allowing us to treat our strings (and translations) as data stored in a text file. We can then use the data file to create drops for the localization team, consume similar drops returned by the localization team, and create formatted localization files to ship with your products.'
         opts.separator ''
         opts.separator 'Commands:'
         opts.separator ''
-        opts.separator '- generate-string-file'
-        opts.separator '    Generates a string file in a certain LANGUAGE given a particular FORMAT. This script will attempt to guess both the language and the format given the filename and extension. For example, "ko.xml" will generate a Korean language file for Android.'
+        opts.separator '- generate-localization-file'
+        opts.separator '    Generates a localization file in a certain LANGUAGE given a particular FORMAT. This script will attempt to guess both the language and the format given the filename and extension. For example, "ko.xml" will generate a Korean language file for Android.'
         opts.separator ''
-        opts.separator '- generate-all-string-files'
-        opts.separator '    Generates all the string files necessary for a given project. The parent directory to all of the locale-specific directories in your project should be specified as the INPUT_OR_OUTPUT_PATH. This command will most often be executed by your build script so that each build always contains the most recent strings.'
+        opts.separator '- generate-all-localization-files'
+        opts.separator '    Generates all the localization files necessary for a given project. The parent directory to all of the locale-specific directories in your project should be specified as the INPUT_OR_OUTPUT_PATH. This command will most often be executed by your build script so that each build always contains the most recent translations.'
         opts.separator ''
-        opts.separator '- consume-string-file'
-        opts.separator '    Slurps all of the strings from a translated strings file into the specified STRINGS_FILE. If you have some files returned to you by your translators you can use this command to incorporate all of their changes. This script will attempt to guess both the language and the format given the filename and extension. For example, "ja.strings" will assume that the file is a Japanese iOS strings file.'
+        opts.separator '- consume-localization-file'
+        opts.separator '    Slurps all of the translations from a localization file into the specified TWINE_FILE. If you have some files returned to you by your translators you can use this command to incorporate all of their changes. This script will attempt to guess both the language and the format given the filename and extension. For example, "ja.strings" will assume that the file is a Japanese iOS strings file.'
         opts.separator ''
-        opts.separator '- consume-all-string-files'
-        opts.separator '    Slurps all of the strings from a directory into the specified STRINGS_FILE. If you have some files returned to you by your translators you can use this command to incorporate all of their changes. This script will attempt to guess both the language and the format given the filename and extension. For example, "ja.strings" will assume that the file is a Japanese iOS strings file.'
+        opts.separator '- consume-all-localization-files'
+        opts.separator '    Slurps all of the translations from a directory into the specified TWINE_FILE. If you have some files returned to you by your translators you can use this command to incorporate all of their changes. This script will attempt to guess both the language and the format given the filename and extension. For example, "ja.strings" will assume that the file is a Japanese iOS strings file.'
         opts.separator ''
         opts.separator '- generate-loc-drop'
-        opts.separator '    Generates a zip archive of strings files in any format. The purpose of this command is to create a very simple archive that can be handed off to a translation team. The translation team can unzip the archive, translate all of the strings in the archived files, zip everything back up, and then hand that final archive back to be consumed by the consume-loc-drop command.'
+        opts.separator '    Generates a zip archive of localization files in a given format. The purpose of this command is to create a very simple archive that can be handed off to a translation team. The translation team can unzip the archive, translate all of the strings in the archived files, zip everything back up, and then hand that final archive back to be consumed by the consume-loc-drop command.'
         opts.separator ''
         opts.separator '- consume-loc-drop'
         opts.separator '    Consumes an archive of translated files. This archive should be in the same format as the one created by the generate-loc-drop command.'
         opts.separator ''
-        opts.separator '- validate-strings-file'
-        opts.separator '    Validates that the given strings file is parseable, contains no duplicates, and that every string has a tag. Exits with a non-zero exit code if those criteria are not met.'
+        opts.separator '- validate-twine-file'
+        opts.separator '    Validates that the given Twine file is parseable, contains no duplicates, and that no key contains invalid characters. Exits with a non-zero exit code if those criteria are not met.'
         opts.separator ''
         opts.separator 'General Options:'
         opts.separator ''
         opts.on('-l', '--lang LANGUAGES', Array, 'The language code(s) to use for the specified action.') do |l|
           options[:languages] = l
         end
-        opts.on('-t', '--tags TAG1,TAG2,TAG3', Array, 'The tag(s) to use for the specified action. Only strings with that tag will be processed. Omit this option to match',
-                                                      '  all strings in the strings data file.') do |t|
+        opts.on('-t', '--tags TAG1,TAG2,TAG3', Array, 'The tag(s) to use for the specified action. Only definitions with that tag will be processed. Omit this option to match',
+                                                      '  all definitions in the Twine data file.') do |t|
           options[:tags] = t
         end
         opts.on('-u', '--[no-]untagged', 'If you have specified tags using the --tags flag, then only those tags will be selected. If you also want to select',
-                                         '  all strings that are untagged, then you can specify this option to do so.') do |u|
+                                         '  all definitions that are untagged, then you can specify this option to do so.') do |u|
           options[:untagged] = u
         end
         formats = Formatters.formatters.map(&:format_name).map(&:downcase)
@@ -61,36 +61,36 @@ module Twine
                                                   "  Additional formatters can be placed in the formats/ directory.") do |f|
           options[:format] = f
         end
-        opts.on('-a', '--[no-]consume-all', 'Normally, when consuming a string file, Twine will ignore any string keys that do not exist in your master file.') do |a|
+        opts.on('-a', '--[no-]consume-all', 'Normally, when consuming a localization file, Twine will ignore any translation keys that do not exist in your Twine file.') do |a|
           options[:consume_all] = true
         end
         opts.on('-i', '--include SET', [:all, :translated, :untranslated],
-                                        "This flag will determine which strings are included when generating strings files. It's possible values:",
-                                        "  all: All strings both translated and untranslated for the specified language are included. This is the default value.",
-                                        "  translated: Only translated strings are included.",
-                                        "  untranslated: Only untranslated strings are included.") do |i|
+                                        "This flag will determine which definitions are included when generating localization files. It's possible values are:",
+                                        "  all: All definitions both translated and untranslated for the specified language are included. This is the default value.",
+                                        "  translated: Only definitions with translation for the specified language are included.",
+                                        "  untranslated: Only definitions without translation for the specified language are included.") do |i|
           options[:include] = i
         end
-        opts.on('-o', '--output-file OUTPUT_FILE', 'Write the new strings database to this file instead of replacing the original file. This flag is only useful when',
-                                                   '  running the consume-string-file or consume-loc-drop commands.') do |o|
+        opts.on('-o', '--output-file OUTPUT_FILE', 'Write a new Twine file at this location instead of replacing the original file. This flag is only useful when',
+                                                   '  running the consume-localization-file or consume-loc-drop commands.') do |o|
           options[:output_path] = o
         end
-        opts.on('-n', '--file-name FILE_NAME', 'When running the generate-all-string-files command, this flag may be used to overwrite the default file name of the format.') do |n|
+        opts.on('-n', '--file-name FILE_NAME', 'When running the generate-all-localization-files command, this flag may be used to overwrite the default file name of the format.') do |n|
           options[:file_name] = n
         end
-        opts.on('-r', '--[no-]create-folders', "When running the generate-all-string-files command, this flag may be used to create output folders for all languages,",
+        opts.on('-r', '--[no-]create-folders', "When running the generate-all-localization-files command, this flag may be used to create output folders for all languages,",
                                                "  if they  don't exist yet. As a result all languages will be exported, not only the ones where an output folder already",
                                                "  exists.") do |r|
           options[:create_folders] = r
         end
-        opts.on('-d', '--developer-language LANG', 'When writing the strings data file, set the specified language as the "developer language". In practice, this just',
-                                                   '  means that this language will appear first in the strings data file. When generating files this language will be',
-                                                   '  used as default language and its translations will be used if a key is not localized for the output language.') do |d|
+        opts.on('-d', '--developer-language LANG', 'When writing the Twine data file, set the specified language as the "developer language". In practice, this just',
+                                                   '  means that this language will appear first in the Twine data file. When generating files this language will be',
+                                                   '  used as default language and its translations will be used if a definition is not localized for the output language.') do |d|
           options[:developer_language] = d
         end
-        opts.on('-c', '--[no-]consume-comments', 'Normally, when consuming a string file, Twine will ignore all comments in the file. With this flag set, any comments',
-                                                 '  encountered will be read and parsed into the strings data file. This is especially useful when creating your first',
-                                                 '  strings data file from an existing project.') do |c|
+        opts.on('-c', '--[no-]consume-comments', 'Normally, when consuming a localization file, Twine will ignore all comments in the file. With this flag set, any comments',
+                                                 '  encountered will be read and parsed into the Twine data file. This is especially useful when creating your first',
+                                                 '  Twine data file from an existing project.') do |c|
           options[:consume_comments] = c
         end
         opts.on('-e', '--encoding ENCODING', 'Twine defaults to encoding all output files in UTF-8. This flag will tell Twine to use an alternate encoding for these',
@@ -99,10 +99,10 @@ module Twine
                                              '  UTF-16LE or UTF16-BE.') do |e|
           options[:output_encoding] = e
         end
-        opts.on('--[no-]validate', 'Validate the strings file before formatting it.') do |validate|
+        opts.on('--[no-]validate', 'Validate the Twine file before formatting it.') do |validate|
           options[:validate] = validate
         end
-        opts.on('-p', '--[no-]pedantic', 'When validating a strings file, perform additional checks that go beyond pure validity (like presence of tags).') do |p|
+        opts.on('-p', '--[no-]pedantic', 'When validating a Twine file, perform additional checks that go beyond pure validity (like presence of tags).') do |p|
           options[:pedantic] = p
         end
         opts.on('-h', '--help', 'Show this message.') do |h|
@@ -116,13 +116,13 @@ module Twine
         opts.separator ''
         opts.separator 'Examples:'
         opts.separator ''
-        opts.separator '> twine generate-string-file strings.txt ko.xml --tags FT'
-        opts.separator '> twine generate-all-string-files strings.txt Resources/Locales/ --tags FT,FB'
-        opts.separator '> twine consume-string-file strings.txt ja.strings'
-        opts.separator '> twine consume-all-string-files strings.txt Resources/Locales/ --developer-language en --tags DefaultTag1,DefaultTag2'
-        opts.separator '> twine generate-loc-drop strings.txt LocDrop5.zip --tags FT,FB --format android --lang de,en,en-GB,ja,ko'
-        opts.separator '> twine consume-loc-drop strings.txt LocDrop5.zip'
-        opts.separator '> twine validate-strings-file strings.txt'
+        opts.separator '> twine generate-localization-file twine.txt ko.xml --tags FT'
+        opts.separator '> twine generate-all-localization-files twine.txt Resources/Locales/ --tags FT,FB'
+        opts.separator '> twine consume-localization-file twine.txt ja.strings'
+        opts.separator '> twine consume-all-localization-files twine.txt Resources/Locales/ --developer-language en --tags DefaultTag1,DefaultTag2'
+        opts.separator '> twine generate-loc-drop twine.txt LocDrop5.zip --tags FT,FB --format android --lang de,en,en-GB,ja,ko'
+        opts.separator '> twine consume-loc-drop twine.txt LocDrop5.zip'
+        opts.separator '> twine validate-twine-file twine.txt'
       end
       begin
         parser.parse! args
@@ -136,6 +136,19 @@ module Twine
         exit false
       end
 
+      # TODO: Remove this mapping of deprecated commands some time in the future - added on 31.03.
+      deprecated_command_mappings = { 
+        'generate-string-file' => 'generate-localization-file',
+        'generate-all-string-file' => 'generate-all-localization-files',
+        'consume-string-file' => 'consume-localization-file',
+        'consume-all-string-files' => 'consume-all-localization-files'
+      }
+      mapped_command = deprecated_command_mappings[args[0]]
+      if mapped_command
+        Twine::stderr.puts "WARNING: Twine commands names have changed. `#{args[0]}` is now `#{mapped_command}`. The old command is deprecated will soon stop working. For more information please check the documentation at https://github.com/mobiata/twine"
+        args[0] = mapped_command
+      end
+
       number_of_needed_arguments = NEEDED_COMMAND_ARGUMENTS[args[0]]
       unless number_of_needed_arguments
         raise Twine::Error.new "Invalid command: #{args[0]}"
@@ -143,9 +156,9 @@ module Twine
       options[:command] = args[0]
 
       if args.length < 2
-        raise Twine::Error.new 'You must specify your strings file.'
+        raise Twine::Error.new 'You must specify your twine file.'
       end
-      options[:strings_file] = args[1]
+      options[:twine_file] = args[1]
 
       if args.length < number_of_needed_arguments
         raise Twine::Error.new 'Not enough arguments.'
@@ -154,19 +167,19 @@ module Twine
       end
 
       case options[:command]
-      when 'generate-string-file'
+      when 'generate-localization-file'
         options[:output_path] = args[2]
         if options[:languages] and options[:languages].length > 1
-          raise Twine::Error.new 'Please only specify a single language for the generate-string-file command.'
+          raise Twine::Error.new 'Please only specify a single language for the generate-localization-file command.'
         end
-      when 'generate-all-string-files'
+      when 'generate-all-localization-files'
         options[:output_path] = args[2]
-      when 'consume-string-file'
+      when 'consume-localization-file'
         options[:input_path] = args[2]
         if options[:languages] and options[:languages].length > 1
-          raise Twine::Error.new 'Please only specify a single language for the consume-string-file command.'
+          raise Twine::Error.new 'Please only specify a single language for the consume-localization-file command.'
         end
-      when 'consume-all-string-files'
+      when 'consume-all-localization-files'
         options[:input_path] = args[2]
       when 'generate-loc-drop'
         options[:output_path] = args[2]
@@ -175,7 +188,7 @@ module Twine
         end
       when 'consume-loc-drop'
         options[:input_path] = args[2]
-      when 'validate-strings-file'
+      when 'validate-twine-file'
       end
 
       return options
diff --git a/lib/twine/formatters/abstract.rb b/lib/twine/formatters/abstract.rb
index 012346e..c337a60 100644
--- a/lib/twine/formatters/abstract.rb
+++ b/lib/twine/formatters/abstract.rb
@@ -3,11 +3,11 @@ require 'fileutils'
 module Twine
   module Formatters
     class Abstract
-      attr_accessor :strings
+      attr_accessor :twine_file
       attr_accessor :options
 
       def initialize
-        @strings = StringsFile.new
+        @twine_file = TwineFile.new
         @options = {}
       end
 
@@ -30,47 +30,47 @@ module Twine
       def set_translation_for_key(key, lang, value)
         value = value.gsub("\n", "\\n")
 
-        if @strings.strings_map.include?(key)
-          row = @strings.strings_map[key]
-          reference = @strings.strings_map[row.reference_key] if row.reference_key
+        if @twine_file.definitions_by_key.include?(key)
+          definition = @twine_file.definitions_by_key[key]
+          reference = @twine_file.definitions_by_key[definition.reference_key] if definition.reference_key
 
           if !reference or value != reference.translations[lang]
-            row.translations[lang] = value
+            definition.translations[lang] = value
           end
         elsif @options[:consume_all]
-          Twine::stderr.puts "Adding new string '#{key}' to strings data file."
-          current_section = @strings.sections.find { |s| s.name == 'Uncategorized' }
+          Twine::stderr.puts "Adding new definition '#{key}' to twine file."
+          current_section = @twine_file.sections.find { |s| s.name == 'Uncategorized' }
           unless current_section
-            current_section = StringsSection.new('Uncategorized')
-            @strings.sections.insert(0, current_section)
+            current_section = TwineSection.new('Uncategorized')
+            @twine_file.sections.insert(0, current_section)
           end
-          current_row = StringsRow.new(key)
-          current_section.rows << current_row
+          current_definition = TwineDefinition.new(key)
+          current_section.definitions << current_definition
           
           if @options[:tags] && @options[:tags].length > 0
-            current_row.tags = @options[:tags]            
+            current_definition.tags = @options[:tags]            
           end
           
-          @strings.strings_map[key] = current_row
-          @strings.strings_map[key].translations[lang] = value
+          @twine_file.definitions_by_key[key] = current_definition
+          @twine_file.definitions_by_key[key].translations[lang] = value
         else
-          Twine::stderr.puts "Warning: '#{key}' not found in strings data file."
+          Twine::stderr.puts "Warning: '#{key}' not found in twine file."
         end
-        if !@strings.language_codes.include?(lang)
-          @strings.add_language_code(lang)
+        if !@twine_file.language_codes.include?(lang)
+          @twine_file.add_language_code(lang)
         end
       end
 
       def set_comment_for_key(key, comment)
         return unless @options[:consume_comments]
         
-        if @strings.strings_map.include?(key)
-          row = @strings.strings_map[key]
+        if @twine_file.definitions_by_key.include?(key)
+          definition = @twine_file.definitions_by_key[key]
           
-          reference = @strings.strings_map[row.reference_key] if row.reference_key
+          reference = @twine_file.definitions_by_key[definition.reference_key] if definition.reference_key
 
           if !reference or comment != reference.raw_comment
-            row.comment = comment
+            definition.comment = comment
           end
         end
       end
@@ -88,35 +88,35 @@ module Twine
       end
 
       def format_file(lang)
-        output_processor = Processors::OutputProcessor.new(@strings, @options)
-        processed_strings = output_processor.process(lang)
+        output_processor = Processors::OutputProcessor.new(@twine_file, @options)
+        processed_twine_file = output_processor.process(lang)
 
-        return nil if processed_strings.strings_map.empty?
+        return nil if processed_twine_file.definitions_by_key.empty?
 
         header = format_header(lang)
         result = ""
         result += header + "\n" if header
-        result += format_sections(processed_strings, lang)
+        result += format_sections(processed_twine_file, lang)
       end
 
       def format_header(lang)
       end
 
-      def format_sections(strings, lang)
-        sections = strings.sections.map { |section| format_section(section, lang) }
+      def format_sections(twine_file, lang)
+        sections = twine_file.sections.map { |section| format_section(section, lang) }
         sections.compact.join("\n")
       end
 
       def format_section_header(section)
       end
 
-      def should_include_row(row, lang)
-        row.translated_string_for_lang(lang)
+      def should_include_definition(definition, lang)
+        return !definition.translation_for_lang(lang).nil?
       end
 
       def format_section(section, lang)
-        rows = section.rows.select { |row| should_include_row(row, lang) }
-        return if rows.empty?
+        definitions = section.definitions.select { |definition| should_include_definition(definition, lang) }
+        return if definitions.empty?
 
         result = ""
 
@@ -125,22 +125,22 @@ module Twine
           result += "\n#{section_header}" if section_header
         end
 
-        rows.map! { |row| format_row(row, lang) }
-        rows.compact! # remove nil entries
-        rows.map! { |row| "\n#{row}" }  # prepend newline
-        result += rows.join
+        definitions.map! { |definition| format_definition(definition, lang) }
+        definitions.compact! # remove nil definitions
+        definitions.map! { |definition| "\n#{definition}" }  # prepend newline
+        result += definitions.join
       end
 
-      def format_row(row, lang)
-        [format_comment(row, lang), format_key_value(row, lang)].compact.join
+      def format_definition(definition, lang)
+        [format_comment(definition, lang), format_key_value(definition, lang)].compact.join
       end
 
-      def format_comment(row, lang)
+      def format_comment(definition, lang)
       end
 
-      def format_key_value(row, lang)
-        value = row.translated_string_for_lang(lang)
-        key_value_pattern % { key: format_key(row.key.dup), value: format_value(value.dup) }
+      def format_key_value(definition, lang)
+        value = definition.translation_for_lang(lang)
+        key_value_pattern % { key: format_key(definition.key.dup), value: format_value(value.dup) }
       end
 
       def key_value_pattern
diff --git a/lib/twine/formatters/android.rb b/lib/twine/formatters/android.rb
index 448826d..caddec8 100644
--- a/lib/twine/formatters/android.rb
+++ b/lib/twine/formatters/android.rb
@@ -37,7 +37,7 @@ module Twine
         path_arr = path.split(File::SEPARATOR)
         path_arr.each do |segment|
           if segment == 'values'
-            return @strings.language_codes[0]
+            return @twine_file.language_codes[0]
           else
             # The language is defined by a two-letter ISO 639-1 language code, optionally followed by a two letter ISO 3166-1-alpha-2 region code (preceded by lowercase "r").
             # see http://developer.android.com/guide/topics/resources/providing-resources.html#AlternativeResources
@@ -105,7 +105,7 @@ module Twine
         "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n<!-- Android Strings File -->\n<!-- Generated by Twine #{Twine::VERSION} -->\n<!-- Language: #{lang} -->"
       end
 
-      def format_sections(strings, lang)
+      def format_sections(twine_file, lang)
         result = '<resources>'
         
         result += super + "\n"
@@ -117,8 +117,8 @@ module Twine
         "\t<!-- SECTION: #{section.name} -->"
       end
 
-      def format_comment(row, lang)
-        "\t<!-- #{row.comment.gsub('--', '—')} -->\n" if row.comment
+      def format_comment(definition, lang)
+        "\t<!-- #{definition.comment.gsub('--', '—')} -->\n" if definition.comment
       end
 
       def key_value_pattern
@@ -137,7 +137,7 @@ module Twine
         #  4) escape non resource identifier @ signs (http://developer.android.com/guide/topics/resources/accessing-resources.html#ResourcesFromXml)
         resource_identifier_regex = /@(?!([a-z\.]+:)?[a-z+]+\/[a-zA-Z_]+)/   # @[<package_name>:]<resource_type>/<resource_name>
         value.gsub!(resource_identifier_regex, '\@')
-        #  5) replace beginning and end spaces with \0020. Otherwise Android strips them.
+        #  5) replace beginning and end spaces with \u0020. Otherwise Android strips them.
         value.gsub(/\A *| *\z/) { |spaces| '\u0020' * spaces.length }
       end
 
diff --git a/lib/twine/formatters/apple.rb b/lib/twine/formatters/apple.rb
index 9546e2b..056ada7 100644
--- a/lib/twine/formatters/apple.rb
+++ b/lib/twine/formatters/apple.rb
@@ -73,8 +73,8 @@ module Twine
         "\"%{key}\" = \"%{value}\";\n"
       end
 
-      def format_comment(row, lang)
-        "/* #{row.comment.gsub('*/', '* /')} */\n" if row.comment
+      def format_comment(definition, lang)
+        "/* #{definition.comment.gsub('*/', '* /')} */\n" if definition.comment
       end
 
       def format_key(key)
diff --git a/lib/twine/formatters/django.rb b/lib/twine/formatters/django.rb
index b63657e..dd60c4f 100644
--- a/lib/twine/formatters/django.rb
+++ b/lib/twine/formatters/django.rb
@@ -63,7 +63,7 @@ module Twine
       end
 
       def format_file(lang)
-        @default_lang = @strings.language_codes[0]
+        @default_lang = @twine_file.language_codes[0]
         result = super
         @default_lang = nil
         result
@@ -77,12 +77,12 @@ module Twine
         "#--------- #{section.name} ---------#\n"
       end
 
-      def format_row(row, lang)
-        [format_comment(row, lang), format_base_translation(row), format_key_value(row, lang)].compact.join
+      def format_definition(definition, lang)
+        [format_comment(definition, lang), format_base_translation(definition), format_key_value(definition, lang)].compact.join
       end
 
-      def format_base_translation(row)
-        base_translation = row.translations[@default_lang]
+      def format_base_translation(definition)
+        base_translation = definition.translations[@default_lang]
         "# base translation: \"#{base_translation}\"\n" if base_translation
       end
 
@@ -91,8 +91,8 @@ module Twine
         "msgstr \"%{value}\"\n"
       end
 
-      def format_comment(row, lang)
-        "#. #{escape_quotes(row.comment)}\n" if row.comment
+      def format_comment(definition, lang)
+        "#. #{escape_quotes(definition.comment)}\n" if definition.comment
       end
 
       def format_key(key)
diff --git a/lib/twine/formatters/flash.rb b/lib/twine/formatters/flash.rb
index 8cc29da..3aaee70 100644
--- a/lib/twine/formatters/flash.rb
+++ b/lib/twine/formatters/flash.rb
@@ -44,7 +44,7 @@ module Twine
         end
       end
 
-      def format_sections(strings, lang)
+      def format_sections(twine_file, lang)
         super + "\n"
       end
 
@@ -56,8 +56,8 @@ module Twine
         "## #{section.name} ##\n"
       end
 
-      def format_comment(row, lang)
-        "# #{row.comment}\n" if row.comment
+      def format_comment(definition, lang)
+        "# #{definition.comment}\n" if definition.comment
       end
 
       def key_value_pattern
diff --git a/lib/twine/formatters/gettext.rb b/lib/twine/formatters/gettext.rb
index 71b9a84..90553bd 100644
--- a/lib/twine/formatters/gettext.rb
+++ b/lib/twine/formatters/gettext.rb
@@ -64,7 +64,7 @@ module Twine
       end
 
       def format_file(lang)
-        @default_lang = strings.language_codes[0]
+        @default_lang = twine_file.language_codes[0]
         result = super
         @default_lang = nil
         result
@@ -78,25 +78,25 @@ module Twine
         "# SECTION: #{section.name}"
       end
 
-      def should_include_row(row, lang)
-        super and row.translated_string_for_lang(@default_lang)
+      def should_include_definition(definition, lang)
+        super and !definition.translation_for_lang(@default_lang).nil?
       end
 
-      def format_comment(row, lang)
-        "#. \"#{escape_quotes(row.comment)}\"\n" if row.comment
+      def format_comment(definition, lang)
+        "#. \"#{escape_quotes(definition.comment)}\"\n" if definition.comment
       end
 
-      def format_key_value(row, lang)
-        value = row.translated_string_for_lang(lang)
-        [format_key(row.key.dup), format_base_translation(row), format_value(value.dup)].compact.join
+      def format_key_value(definition, lang)
+        value = definition.translation_for_lang(lang)
+        [format_key(definition.key.dup), format_base_translation(definition), format_value(value.dup)].compact.join
       end
 
       def format_key(key)
         "msgctxt \"#{key}\"\n"
       end
 
-      def format_base_translation(row)
-        "msgid \"#{row.translations[@default_lang]}\"\n"
+      def format_base_translation(definition)
+        "msgid \"#{definition.translations[@default_lang]}\"\n"
       end
 
       def format_value(value)
diff --git a/lib/twine/formatters/jquery.rb b/lib/twine/formatters/jquery.rb
index 310f041..8d60116 100644
--- a/lib/twine/formatters/jquery.rb
+++ b/lib/twine/formatters/jquery.rb
@@ -48,8 +48,8 @@ module Twine
         "{\n#{super}\n}\n"
       end
 
-      def format_sections(strings, lang)
-        sections = strings.sections.map { |section| format_section(section, lang) }
+      def format_sections(twine_file, lang)
+        sections = twine_file.sections.map { |section| format_section(section, lang) }
         sections.join(",\n\n")
       end
 
@@ -57,11 +57,11 @@ module Twine
       end
 
       def format_section(section, lang)
-        rows = section.rows.dup
+        definitions = section.definitions.dup
 
-        rows.map! { |row| format_row(row, lang) }
-        rows.compact! # remove nil entries
-        rows.join(",\n")
+        definitions.map! { |definition| format_definition(definition, lang) }
+        definitions.compact! # remove nil definitions
+        definitions.join(",\n")
       end
 
       def key_value_pattern
diff --git a/lib/twine/formatters/tizen.rb b/lib/twine/formatters/tizen.rb
index 8c9fae8..21ba771 100644
--- a/lib/twine/formatters/tizen.rb
+++ b/lib/twine/formatters/tizen.rb
@@ -94,7 +94,7 @@ module Twine
         "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n<!-- Tizen Strings File -->\n<!-- Generated by Twine #{Twine::VERSION} -->\n<!-- Language: #{lang} -->"
       end
 
-      def format_sections(strings, lang)
+      def format_sections(twine_file, lang)
         result = '<string_table  Bversion="2.0.0.201311071819" Dversion="20120315">'
         
         result += super + "\n"
@@ -106,8 +106,8 @@ module Twine
         "\t<!-- SECTION: #{section.name} -->"
       end
 
-      def format_comment(row, lang)
-        "\t<!-- #{row.comment.gsub('--', '—')} -->\n" if row.comment
+      def format_comment(definition, lang)
+        "\t<!-- #{definition.comment.gsub('--', '—')} -->\n" if definition.comment
       end
 
       def key_value_pattern
diff --git a/lib/twine/output_processor.rb b/lib/twine/output_processor.rb
index 405e37a..8924ad1 100644
--- a/lib/twine/output_processor.rb
+++ b/lib/twine/output_processor.rb
@@ -2,13 +2,13 @@ module Twine
   module Processors
 
     class OutputProcessor
-      def initialize(strings, options)
-        @strings = strings
+      def initialize(twine_file, options)
+        @twine_file = twine_file
         @options = options
       end
 
       def default_language
-        @options[:developer_language] || @strings.language_codes[0]
+        @options[:developer_language] || @twine_file.language_codes[0]
       end
 
       def fallback_languages(language)
@@ -20,30 +20,30 @@ module Twine
       end
 
       def process(language)
-        result = StringsFile.new
+        result = TwineFile.new
 
-        result.language_codes.concat @strings.language_codes
-        @strings.sections.each do |section|
-          new_section = StringsSection.new section.name
+        result.language_codes.concat @twine_file.language_codes
+        @twine_file.sections.each do |section|
+          new_section = TwineSection.new section.name
 
-          section.rows.each do |row|
-            next unless row.matches_tags?(@options[:tags], @options[:untagged])
+          section.definitions.each do |definition|
+            next unless definition.matches_tags?(@options[:tags], @options[:untagged])
 
-            value = row.translated_string_for_lang(language)
+            value = definition.translation_for_lang(language)
 
             next if value && @options[:include] == :untranslated
 
             if value.nil? && @options[:include] != :translated
-              value = row.translated_string_for_lang(fallback_languages(language))
+              value = definition.translation_for_lang(fallback_languages(language))
             end
 
             next unless value
 
-            new_row = row.dup
-            new_row.translations[language] = value
+            new_definition = definition.dup
+            new_definition.translations[language] = value
 
-            new_section.rows << new_row
-            result.strings_map[new_row.key] = new_row
+            new_section.definitions << new_definition
+            result.definitions_by_key[new_definition.key] = new_definition
           end
 
           result.sections << new_section
diff --git a/lib/twine/runner.rb b/lib/twine/runner.rb
index 92a6c71..3f14116 100644
--- a/lib/twine/runner.rb
+++ b/lib/twine/runner.rb
@@ -8,42 +8,42 @@ module Twine
     def self.run(args)
       options = CLI.parse(args)
       
-      strings = StringsFile.new
-      strings.read options[:strings_file]
-      runner = new(options, strings)
+      twine_file = TwineFile.new
+      twine_file.read options[:twine_file]
+      runner = new(options, twine_file)
 
       case options[:command]
-      when 'generate-string-file'
-        runner.generate_string_file
-      when 'generate-all-string-files'
-        runner.generate_all_string_files
-      when 'consume-string-file'
-        runner.consume_string_file
-      when 'consume-all-string-files'
-        runner.consume_all_string_files
+      when 'generate-localization-file'
+        runner.generate_localization_file
+      when 'generate-all-localization-files'
+        runner.generate_all_localization_files
+      when 'consume-localization-file'
+        runner.consume_localization_file
+      when 'consume-all-localization-files'
+        runner.consume_all_localization_files
       when 'generate-loc-drop'
         runner.generate_loc_drop
       when 'consume-loc-drop'
         runner.consume_loc_drop
-      when 'validate-strings-file'
-        runner.validate_strings_file
+      when 'validate-twine-file'
+        runner.validate_twine_file
       end
     end
 
-    def initialize(options = {}, strings = StringsFile.new)
+    def initialize(options = {}, twine_file = TwineFile.new)
       @options = options
-      @strings = strings
+      @twine_file = twine_file
     end
 
-    def write_strings_data(path)
+    def write_twine_data(path)
       if @options[:developer_language]
-        @strings.set_developer_language_code(@options[:developer_language])
+        @twine_file.set_developer_language_code(@options[:developer_language])
       end
-      @strings.write(path)
+      @twine_file.write(path)
     end
 
-    def generate_string_file
-      validate_strings_file if @options[:validate]
+    def generate_localization_file
+      validate_twine_file if @options[:validate]
 
       lang = nil
       lang = @options[:languages][0] if @options[:languages]
@@ -51,13 +51,13 @@ module Twine
       formatter, lang = prepare_read_write(@options[:output_path], lang)
       output = formatter.format_file(lang)
 
-      raise Twine::Error.new "Nothing to generate! The resulting file would not contain any strings." unless output
+      raise Twine::Error.new "Nothing to generate! The resulting file would not contain any translations." unless output
 
       IO.write(@options[:output_path], output, encoding: encoding)
     end
 
-    def generate_all_string_files
-      validate_strings_file if @options[:validate]
+    def generate_all_localization_files
+      validate_twine_file if @options[:validate]
 
       if !File.directory?(@options[:output_path])
         if @options[:create_folders]
@@ -76,7 +76,7 @@ module Twine
 
       file_name = @options[:file_name] || formatter.default_file_name
       if @options[:create_folders]
-        @strings.language_codes.each do |lang|
+        @twine_file.language_codes.each do |lang|
           output_path = File.join(@options[:output_path], formatter.output_path_for_language(lang))
 
           FileUtils.mkdir_p(output_path)
@@ -85,7 +85,7 @@ module Twine
 
           output = formatter.format_file(lang)
           unless output
-            Twine::stderr.puts "Skipping file at path #{file_path} since it would not contain any strings."
+            Twine::stderr.puts "Skipping file at path #{file_path} since it would not contain any translations."
             next
           end
 
@@ -107,7 +107,7 @@ module Twine
           file_path = File.join(output_path, file_name)
           output = formatter.format_file(lang)
           unless output
-            Twine::stderr.puts "Skipping file at path #{file_path} since it would not contain any strings."
+            Twine::stderr.puts "Skipping file at path #{file_path} since it would not contain any translations."
             next
           end
 
@@ -121,18 +121,18 @@ module Twine
 
     end
 
-    def consume_string_file
+    def consume_localization_file
       lang = nil
       if @options[:languages]
         lang = @options[:languages][0]
       end
 
-      read_string_file(@options[:input_path], lang)
-      output_path = @options[:output_path] || @options[:strings_file]
-      write_strings_data(output_path)
+      read_localization_file(@options[:input_path], lang)
+      output_path = @options[:output_path] || @options[:twine_file]
+      write_twine_data(output_path)
     end
 
-    def consume_all_string_files
+    def consume_all_localization_files
       if !File.directory?(@options[:input_path])
         raise Twine::Error.new("Directory does not exist: #{@options[:output_path]}")
       end
@@ -140,19 +140,19 @@ module Twine
       Dir.glob(File.join(@options[:input_path], "**/*")) do |item|
         if File.file?(item)
           begin
-            read_string_file(item)
+            read_localization_file(item)
           rescue Twine::Error => e
             Twine::stderr.puts "#{e.message}"
           end
         end
       end
 
-      output_path = @options[:output_path] || @options[:strings_file]
-      write_strings_data(output_path)
+      output_path = @options[:output_path] || @options[:twine_file]
+      write_twine_data(output_path)
     end
 
     def generate_loc_drop
-      validate_strings_file if @options[:validate]
+      validate_twine_file if @options[:validate]
       
       require_rubyzip
 
@@ -165,7 +165,7 @@ module Twine
           zipfile.mkdir('Locales')
 
           formatter = formatter_for_format(@options[:format])
-          @strings.language_codes.each do |lang|
+          @twine_file.language_codes.each do |lang|
             if @options[:languages] == nil || @options[:languages].length == 0 || @options[:languages].include?(lang)
               file_name = lang + formatter.extension
               temp_path = File.join(temp_dir, file_name)
@@ -173,7 +173,7 @@ module Twine
 
               output = formatter.format_file(lang)
               unless output
-                Twine::stderr.puts "Skipping file #{file_name} since it would not contain any strings."
+                Twine::stderr.puts "Skipping file #{file_name} since it would not contain any translations."
                 next
               end
               
@@ -201,7 +201,7 @@ module Twine
             FileUtils.mkdir_p(File.dirname(real_path))
             zipfile.extract(entry.name, real_path)
             begin
-              read_string_file(real_path)
+              read_localization_file(real_path)
             rescue Twine::Error => e
               Twine::stderr.puts "#{e.message}"
             end
@@ -209,28 +209,28 @@ module Twine
         end
       end
 
-      output_path = @options[:output_path] || @options[:strings_file]
-      write_strings_data(output_path)
+      output_path = @options[:output_path] || @options[:twine_file]
+      write_twine_data(output_path)
     end
 
-    def validate_strings_file
-      total_strings = 0
+    def validate_twine_file
+      total_definitions = 0
       all_keys = Set.new
       duplicate_keys = Set.new
       keys_without_tags = Set.new
       invalid_keys = Set.new
       valid_key_regex = /^[A-Za-z0-9_]+$/
 
-      @strings.sections.each do |section|
-        section.rows.each do |row|
-          total_strings += 1
+      @twine_file.sections.each do |section|
+        section.definitions.each do |definition|
+          total_definitions += 1
 
-          duplicate_keys.add(row.key) if all_keys.include? row.key
-          all_keys.add(row.key)
+          duplicate_keys.add(definition.key) if all_keys.include? definition.key
+          all_keys.add(definition.key)
 
-          keys_without_tags.add(row.key) if row.tags == nil or row.tags.length == 0
+          keys_without_tags.add(definition.key) if definition.tags == nil or definition.tags.length == 0
 
-          invalid_keys << row.key unless row.key =~ valid_key_regex
+          invalid_keys << definition.key unless definition.key =~ valid_key_regex
         end
       end
 
@@ -238,14 +238,14 @@ module Twine
       join_keys = lambda { |set| set.map { |k| "  " + k }.join("\n") }
 
       unless duplicate_keys.empty?
-        errors << "Found duplicate string key(s):\n#{join_keys.call(duplicate_keys)}"
+        errors << "Found duplicate key(s):\n#{join_keys.call(duplicate_keys)}"
       end
 
       if @options[:pedantic]
-        if keys_without_tags.length == total_strings
-          errors << "None of your strings have tags."
+        if keys_without_tags.length == total_definitions
+          errors << "None of your definitions have tags."
         elsif keys_without_tags.length > 0
-          errors << "Found strings without tags:\n#{join_keys.call(keys_without_tags)}"
+          errors << "Found definitions without tags:\n#{join_keys.call(keys_without_tags)}"
         end
       end
 
@@ -255,7 +255,7 @@ module Twine
 
       raise Twine::Error.new errors.join("\n\n") unless errors.empty?
 
-      Twine::stdout.puts "#{@options[:strings_file]} is valid."
+      Twine::stdout.puts "#{@options[:twine_file]} is valid."
     end
 
     private
@@ -274,7 +274,7 @@ module Twine
 
     def determine_language_given_path(path)
       code = File.basename(path, File.extname(path))
-      return code if @strings.language_codes.include? code
+      return code if @twine_file.language_codes.include? code
     end
 
     def formatter_for_format(format)
@@ -284,12 +284,12 @@ module Twine
     def find_formatter(&block)
       formatter = Formatters.formatters.find &block
       return nil unless formatter
-      formatter.strings = @strings
+      formatter.twine_file = @twine_file
       formatter.options = @options
       formatter
     end
 
-    def read_string_file(path, lang = nil)
+    def read_localization_file(path, lang = nil)
       unless File.file?(path)
         raise Twine::Error.new("File does not exist: #{path}")
       end
@@ -317,7 +317,7 @@ module Twine
         raise Twine::Error.new "Unable to determine language for #{path}"
       end
 
-      @strings.language_codes << lang unless @strings.language_codes.include? lang
+      @twine_file.language_codes << lang unless @twine_file.language_codes.include? lang
 
       return formatter, lang
     end
diff --git a/lib/twine/stringsfile.rb b/lib/twine/twine_file.rb
similarity index 68%
rename from lib/twine/stringsfile.rb
rename to lib/twine/twine_file.rb
index a494d62..b889828 100644
--- a/lib/twine/stringsfile.rb
+++ b/lib/twine/twine_file.rb
@@ -1,15 +1,5 @@
 module Twine
-  class StringsSection
-    attr_reader :name
-    attr_reader :rows
-
-    def initialize(name)
-      @name = name
-      @rows = []
-    end
-  end
-
-  class StringsRow
+  class TwineDefinition
     attr_reader :key
     attr_accessor :comment
     attr_accessor :tags
@@ -37,7 +27,7 @@ module Twine
         # The user did not specify any tags. Everything passes.
         return true
       elsif @tags == nil
-        # This row has no tags.
+        # This definition has no tags.
         return reference ? reference.matches_tags?(tags, include_untagged) : include_untagged
       elsif @tags.empty?
         return include_untagged
@@ -48,18 +38,28 @@ module Twine
       return false
     end
 
-    def translated_string_for_lang(lang)
+    def translation_for_lang(lang)
       translation = [lang].flatten.map { |l| @translations[l] }.first
 
-      translation = reference.translated_string_for_lang(lang) if translation.nil? && reference
+      translation = reference.translation_for_lang(lang) if translation.nil? && reference
 
       return translation
     end
   end
 
-  class StringsFile
+  class TwineSection
+    attr_reader :name
+    attr_reader :definitions
+
+    def initialize(name)
+      @name = name
+      @definitions = []
+    end
+  end
+
+  class TwineFile
     attr_reader :sections
-    attr_reader :strings_map
+    attr_reader :definitions_by_key
     attr_reader :language_codes
 
     private
@@ -73,7 +73,7 @@ module Twine
 
     def initialize
       @sections = []
-      @strings_map = {}
+      @definitions_by_key = {}
       @language_codes = []
     end
 
@@ -102,7 +102,7 @@ module Twine
       File.open(path, 'r:UTF-8') do |f|
         line_num = 0
         current_section = nil
-        current_row = nil
+        current_definition = nil
         while line = f.gets
           parsed = false
           line.strip!
@@ -115,20 +115,20 @@ module Twine
           if line.length > 4 && line[0, 2] == '[['
             match = /^\[\[(.+)\]\]$/.match(line)
             if match
-              current_section = StringsSection.new(match[1])
+              current_section = TwineSection.new(match[1])
               @sections << current_section
               parsed = true
             end
           elsif line.length > 2 && line[0, 1] == '['
             key = match_key(line)
             if key
-              current_row = StringsRow.new(key)
-              @strings_map[current_row.key] = current_row
+              current_definition = TwineDefinition.new(key)
+              @definitions_by_key[current_definition.key] = current_definition
               if !current_section
-                current_section = StringsSection.new('')
+                current_section = TwineSection.new('')
                 @sections << current_section
               end
-              current_section.rows << current_row
+              current_section.definitions << current_definition
               parsed = true
             end
           else
@@ -141,16 +141,16 @@ module Twine
 
               case key
               when 'comment'
-                current_row.comment = value
+                current_definition.comment = value
               when 'tags'
-                current_row.tags = value.split(',')
+                current_definition.tags = value.split(',')
               when 'ref'
-                current_row.reference_key = value if value
+                current_definition.reference_key = value if value
               else
                 if !@language_codes.include? key
                   add_language_code(key)
                 end
-                current_row.translations[key] = value
+                current_definition.translations[key] = value
               end
               parsed = true
             end
@@ -163,9 +163,9 @@ module Twine
       end
 
       # resolve_references
-      @strings_map.each do |key, row|
-        next unless row.reference_key
-        row.reference = @strings_map[row.reference_key]
+      @definitions_by_key.each do |key, definition|
+        next unless definition.reference_key
+        definition.reference = @definitions_by_key[definition.reference_key]
       end
     end
 
@@ -180,26 +180,26 @@ module Twine
 
           f.puts "[[#{section.name}]]"
 
-          section.rows.each do |row|
-            f.puts "\t[#{row.key}]"
+          section.definitions.each do |definition|
+            f.puts "\t[#{definition.key}]"
 
-            value = write_value(row, dev_lang, f)
-            if !value && !row.reference_key
-              puts "Warning: #{row.key} does not exist in developer language '#{dev_lang}'"
+            value = write_value(definition, dev_lang, f)
+            if !value && !definition.reference_key
+              puts "Warning: #{definition.key} does not exist in developer language '#{dev_lang}'"
             end
             
-            if row.reference_key
-              f.puts "\t\tref = #{row.reference_key}"
+            if definition.reference_key
+              f.puts "\t\tref = #{definition.reference_key}"
             end
-            if row.tags && row.tags.length > 0
-              tag_str = row.tags.join(',')
+            if definition.tags && definition.tags.length > 0
+              tag_str = definition.tags.join(',')
               f.puts "\t\ttags = #{tag_str}"
             end
-            if row.raw_comment and row.raw_comment.length > 0
-              f.puts "\t\tcomment = #{row.raw_comment}"
+            if definition.raw_comment and definition.raw_comment.length > 0
+              f.puts "\t\tcomment = #{definition.raw_comment}"
             end
             @language_codes[1..-1].each do |lang|
-              write_value(row, lang, f)
+              write_value(definition, lang, f)
             end
           end
         end
@@ -208,8 +208,8 @@ module Twine
 
     private
 
-    def write_value(row, language, file)
-      value = row.translations[language]
+    def write_value(definition, language, file)
+      value = definition.translations[language]
       return nil unless value
 
       if value[0] == ' ' || value[-1] == ' ' || (value[0] == '`' && value[-1] == '`')
diff --git a/test/command_test_case.rb b/test/command_test_case.rb
index 0f04718..6457807 100644
--- a/test/command_test_case.rb
+++ b/test/command_test_case.rb
@@ -2,11 +2,11 @@ require 'twine_test_case'
 
 class CommandTestCase < TwineTestCase
   def prepare_mock_formatter(formatter_class)
-    strings = Twine::StringsFile.new
-    strings.language_codes.concat KNOWN_LANGUAGES
+    twine_file = Twine::TwineFile.new
+    twine_file.language_codes.concat KNOWN_LANGUAGES
 
     formatter = formatter_class.new
-    formatter.strings = strings
+    formatter.twine_file = twine_file
     Twine::Formatters.formatters.clear
     Twine::Formatters.formatters << formatter
     formatter
diff --git a/test/test_abstract_formatter.rb b/test/test_abstract_formatter.rb
index 40c6c24..706e893 100644
--- a/test/test_abstract_formatter.rb
+++ b/test/test_abstract_formatter.rb
@@ -5,74 +5,74 @@ class TestAbstractFormatter < TwineTestCase
     def setup
       super
 
-      @strings = build_twine_file 'en', 'fr' do
+      @twine_file = build_twine_file 'en', 'fr' do
         add_section 'Section' do
-          add_row key1: 'value1-english'
-          add_row key2: { en: 'value2-english', fr: 'value2-french' }
+          add_definition key1: 'value1-english'
+          add_definition key2: { en: 'value2-english', fr: 'value2-french' }
         end
       end
 
       @formatter = Twine::Formatters::Abstract.new
-      @formatter.strings = @strings
+      @formatter.twine_file = @twine_file
     end
 
     def test_set_translation_updates_existing_value
       @formatter.set_translation_for_key 'key1', 'en', 'value1-english-updated'
 
-      assert_equal 'value1-english-updated', @strings.strings_map['key1'].translations['en']
+      assert_equal 'value1-english-updated', @twine_file.definitions_by_key['key1'].translations['en']
     end
 
     def test_set_translation_does_not_alter_other_language
       @formatter.set_translation_for_key 'key2', 'en', 'value2-english-updated'
 
-      assert_equal 'value2-french', @strings.strings_map['key2'].translations['fr']
+      assert_equal 'value2-french', @twine_file.definitions_by_key['key2'].translations['fr']
     end
 
     def test_set_translation_escapes_newlines
       @formatter.set_translation_for_key 'key1', 'en', "new\nline"
 
-      assert_equal 'new\nline', @strings.strings_map['key1'].translations['en']
+      assert_equal 'new\nline', @twine_file.definitions_by_key['key1'].translations['en']
     end
 
     def test_set_translation_adds_translation_to_existing_key
       @formatter.set_translation_for_key 'key1', 'fr', 'value1-french'
 
-      assert_equal 'value1-french', @strings.strings_map['key1'].translations['fr']
+      assert_equal 'value1-french', @twine_file.definitions_by_key['key1'].translations['fr']
     end
 
     def test_set_translation_does_not_add_new_key
       @formatter.set_translation_for_key 'new-key', 'en', 'new-key-english'
 
-      assert_nil @strings.strings_map['new-key']
+      assert_nil @twine_file.definitions_by_key['new-key']
     end
 
     def test_set_translation_consume_all_adds_new_key
       formatter = Twine::Formatters::Abstract.new
-      formatter.strings = @strings
+      formatter.twine_file = @twine_file
       formatter.options = { consume_all: true }
       formatter.set_translation_for_key 'new-key', 'en', 'new-key-english'
 
-      assert_equal 'new-key-english', @strings.strings_map['new-key'].translations['en']
+      assert_equal 'new-key-english', @twine_file.definitions_by_key['new-key'].translations['en']
     end
 
     def test_set_translation_consume_all_adds_tags
       random_tag = SecureRandom.uuid
       formatter = Twine::Formatters::Abstract.new
-      formatter.strings = @strings
+      formatter.twine_file = @twine_file
       formatter.options = { consume_all: true, tags: [random_tag] }
       formatter.set_translation_for_key 'new-key', 'en', 'new-key-english'
 
-      assert_equal [random_tag], @strings.strings_map['new-key'].tags
+      assert_equal [random_tag], @twine_file.definitions_by_key['new-key'].tags
     end
 
     def test_set_translation_adds_new_keys_to_category_uncategoriezed
       formatter = Twine::Formatters::Abstract.new
-      formatter.strings = @strings
+      formatter.twine_file = @twine_file
       formatter.options = { consume_all: true }
       formatter.set_translation_for_key 'new-key', 'en', 'new-key-english'
 
-      assert_equal 'Uncategorized', @strings.sections[0].name 
-      assert_equal 'new-key', @strings.sections[0].rows[0].key
+      assert_equal 'Uncategorized', @twine_file.sections[0].name 
+      assert_equal 'new-key', @twine_file.sections[0].definitions[0].key
     end
   end
 
@@ -80,27 +80,27 @@ class TestAbstractFormatter < TwineTestCase
     def setup
       super
 
-      @strings = build_twine_file 'en', 'fr' do
+      @twine_file = build_twine_file 'en', 'fr' do
         add_section 'Section' do
-          add_row refkey: 'ref-value'
-          add_row key: :refkey
+          add_definition refkey: 'ref-value'
+          add_definition key: :refkey
         end
       end
 
       @formatter = Twine::Formatters::Abstract.new
-      @formatter.strings = @strings
+      @formatter.twine_file = @twine_file
     end
 
     def test_set_translation_does_not_add_unchanged_translation
       @formatter.set_translation_for_key 'key', 'en', 'ref-value'
 
-      assert_nil @strings.strings_map['key'].translations['en']
+      assert_nil @twine_file.definitions_by_key['key'].translations['en']
     end
 
     def test_set_translation_adds_changed_translation
       @formatter.set_translation_for_key 'key', 'en', 'changed value'
 
-      assert_equal 'changed value', @strings.strings_map['key'].translations['en']
+      assert_equal 'changed value', @twine_file.definitions_by_key['key'].translations['en']
     end
   end
 
@@ -108,28 +108,28 @@ class TestAbstractFormatter < TwineTestCase
     def setup
       super
 
-      @strings = build_twine_file 'en' do
+      @twine_file = build_twine_file 'en' do
         add_section 'Section' do
-          add_row key: 'value'
+          add_definition key: 'value'
         end
       end
     end
 
     def test_set_comment_for_key_does_not_update_comment
       formatter = Twine::Formatters::Abstract.new
-      formatter.strings = @strings
+      formatter.twine_file = @twine_file
       formatter.set_comment_for_key('key', 'comment')
 
-      assert_nil formatter.strings.strings_map['key'].comment
+      assert_nil formatter.twine_file.definitions_by_key['key'].comment
     end
 
     def test_set_comment_for_key_updates_comment_with_update_comments
       formatter = Twine::Formatters::Abstract.new
-      formatter.strings = @strings
+      formatter.twine_file = @twine_file
       formatter.options = { consume_comments: true }
       formatter.set_comment_for_key('key', 'comment')
 
-      assert_equal 'comment', formatter.strings.strings_map['key'].comment
+      assert_equal 'comment', formatter.twine_file.definitions_by_key['key'].comment
     end
   end
 
@@ -137,28 +137,28 @@ class TestAbstractFormatter < TwineTestCase
     def setup
       super
 
-      @strings = build_twine_file 'en' do
+      @twine_file = build_twine_file 'en' do
         add_section 'Section' do
-          add_row refkey: 'ref-value', comment: 'reference comment'
-          add_row key: 'value', ref: :refkey
+          add_definition refkey: 'ref-value', comment: 'reference comment'
+          add_definition key: 'value', ref: :refkey
         end
       end
 
       @formatter = Twine::Formatters::Abstract.new
-      @formatter.strings = @strings
+      @formatter.twine_file = @twine_file
       @formatter.options = { consume_comments: true }
     end
 
     def test_set_comment_does_not_add_unchanged_comment
       @formatter.set_comment_for_key 'key', 'reference comment'
       
-      assert_nil @strings.strings_map['key'].raw_comment
+      assert_nil @twine_file.definitions_by_key['key'].raw_comment
     end
 
     def test_set_comment_adds_changed_comment
       @formatter.set_comment_for_key 'key', 'changed comment'
 
-      assert_equal 'changed comment', @strings.strings_map['key'].raw_comment
+      assert_equal 'changed comment', @twine_file.definitions_by_key['key'].raw_comment
     end
   end
 
diff --git a/test/test_cli.rb b/test/test_cli.rb
index 362bb00..55d7787 100644
--- a/test/test_cli.rb
+++ b/test/test_cli.rb
@@ -4,7 +4,7 @@ class CLITestCase < TwineTestCase
   def setup
     super
 
-    @strings_file_path = File.join @output_dir, SecureRandom.uuid
+    @twine_file_path = File.join @output_dir, SecureRandom.uuid
     @input_path = File.join @output_dir, SecureRandom.uuid
     @input_dir = @output_dir
   end
@@ -13,205 +13,205 @@ class CLITestCase < TwineTestCase
     @options = Twine::CLI::parse command.split
   end
 
-  class TestValidateStringsFile < CLITestCase
+  class TestValidateTwineFile < CLITestCase
     def test_command
-      parse "validate-strings-file #{@strings_file_path}"
+      parse "validate-twine-file #{@twine_file_path}"
 
-      assert_equal 'validate-strings-file', @options[:command]
-      assert_equal @strings_file_path, @options[:strings_file]
+      assert_equal 'validate-twine-file', @options[:command]
+      assert_equal @twine_file_path, @options[:twine_file]
     end
 
     def test_pedantic
-      parse "validate-strings-file #{@strings_file_path} --pedantic"
+      parse "validate-twine-file #{@twine_file_path} --pedantic"
       assert @options[:pedantic]
     end
 
     def test_missing_parameter
       assert_raises Twine::Error do
-        parse 'validate-strings-file'
+        parse 'validate-twine-file'
       end
     end
 
     def test_extra_parameter
       assert_raises Twine::Error do
-        parse 'validate-strings-file strings extra'
+        parse 'validate-twine-file twine_file extra'
       end
     end
   end
 
-  class TestGenerateStringFile < CLITestCase
+  class TestGenerateLocalizationFile < CLITestCase
     def test_command
-      parse "generate-string-file #{@strings_file_path} #{@output_path}"
+      parse "generate-localization-file #{@twine_file_path} #{@output_path}"
 
-      assert_equal 'generate-string-file', @options[:command]
-      assert_equal @strings_file_path, @options[:strings_file]
+      assert_equal 'generate-localization-file', @options[:command]
+      assert_equal @twine_file_path, @options[:twine_file]
       assert_equal @output_path, @options[:output_path]
     end
 
     def test_missing_parameter
       assert_raises Twine::Error do
-        parse 'generate-string-file strings'
+        parse 'generate-localization-file twine_file'
       end
     end
 
     def test_validate
-      parse "generate-string-file #{@strings_file_path} #{@output_path} --validate"
+      parse "generate-localization-file #{@twine_file_path} #{@output_path} --validate"
       assert @options[:validate]
     end
 
     def test_extra_parameter
       assert_raises Twine::Error do
-        parse 'generate-string-file strings output extra'
+        parse 'generate-localization-file twine_file output extra'
       end
     end
 
     def test_only_allows_one_language
       assert_raises Twine::Error do
-        parse "generate-string-file strings output --lang en,fr"
+        parse "generate-localization-file twine_file output --lang en,fr"
       end
     end
   end
 
-  class TestGenerateAllStringFiles < CLITestCase
+  class TestGenerateAllLocalizationFiles < CLITestCase
     def test_command
-      parse "generate-all-string-files #{@strings_file_path} #{@output_dir}"
+      parse "generate-all-localization-files #{@twine_file_path} #{@output_dir}"
 
-      assert_equal 'generate-all-string-files', @options[:command]
-      assert_equal @strings_file_path, @options[:strings_file]
+      assert_equal 'generate-all-localization-files', @options[:command]
+      assert_equal @twine_file_path, @options[:twine_file]
       assert_equal @output_dir, @options[:output_path]
     end
 
     def test_missing_parameter
       assert_raises Twine::Error do
-        parse "generate-all-string-files strings"
+        parse "generate-all-localization-files twine_file"
       end
     end
 
     def test_validate
-      parse "generate-all-string-files #{@strings_file_path} #{@output_dir} --validate"
+      parse "generate-all-localization-files #{@twine_file_path} #{@output_dir} --validate"
       assert @options[:validate]
     end
 
     def test_extra_parameter
       assert_raises Twine::Error do
-        parse "generate-all-string-files strings output extra"
+        parse "generate-all-localization-files twine_file output extra"
       end
     end
   end
 
-  class TestConsumeStringFile < CLITestCase
+  class TestConsumeLocalizationFile < CLITestCase
     def test_command
-      parse "consume-string-file #{@strings_file_path} #{@input_path}"
+      parse "consume-localization-file #{@twine_file_path} #{@input_path}"
 
-      assert_equal 'consume-string-file', @options[:command]
-      assert_equal @strings_file_path, @options[:strings_file]
+      assert_equal 'consume-localization-file', @options[:command]
+      assert_equal @twine_file_path, @options[:twine_file]
       assert_equal @input_path, @options[:input_path]
     end
 
     def test_missing_parameter
       assert_raises Twine::Error do
-        parse "consume-string-file strings"
+        parse "consume-localization-file twine_file"
       end
     end
 
     def test_extra_parameter
       assert_raises Twine::Error do
-        parse "consume-string-file strings output extra"
+        parse "consume-localization-file twine_file output extra"
       end
     end
 
     def test_only_allows_one_language
       assert_raises Twine::Error do
-        parse "consume-string-file strings output --lang en,fr"
+        parse "consume-localization-file twine_file output --lang en,fr"
       end
     end
   end
 
-  class TestConsumeAllStringFiles < CLITestCase
+  class TestConsumeAllLocalizationFiles < CLITestCase
     def test_command
-      parse "consume-all-string-files #{@strings_file_path} #{@input_dir}"
+      parse "consume-all-localization-files #{@twine_file_path} #{@input_dir}"
 
-      assert_equal 'consume-all-string-files', @options[:command]
-      assert_equal @strings_file_path, @options[:strings_file]
+      assert_equal 'consume-all-localization-files', @options[:command]
+      assert_equal @twine_file_path, @options[:twine_file]
       assert_equal @input_dir, @options[:input_path]
     end
 
     def test_missing_parameter
       assert_raises Twine::Error do
-        parse "consume-all-string-files strings"
+        parse "consume-all-localization-files twine_file"
       end
     end
 
     def test_extra_parameter
       assert_raises Twine::Error do
-        parse "consume-all-string-files strings output extra"
+        parse "consume-all-localization-files twine_file output extra"
       end
     end
   end
 
   class TestGenerateLocDrop < CLITestCase
     def test_command
-      parse "generate-loc-drop #{@strings_file_path} #{@output_path} --format apple"
+      parse "generate-loc-drop #{@twine_file_path} #{@output_path} --format apple"
 
       assert_equal 'generate-loc-drop', @options[:command]
-      assert_equal @strings_file_path, @options[:strings_file]
+      assert_equal @twine_file_path, @options[:twine_file]
       assert_equal @output_path, @options[:output_path]
     end
 
     def test_missing_parameter
       assert_raises Twine::Error do
-        parse "generate-loc-drop strings --format apple"
+        parse "generate-loc-drop twine_file --format apple"
       end
     end
 
     def test_validate
-      parse "generate-loc-drop #{@strings_file_path} #{@output_path} --format apple --validate"
+      parse "generate-loc-drop #{@twine_file_path} #{@output_path} --format apple --validate"
       assert @options[:validate]
     end
 
     def test_extra_parameter
       assert_raises Twine::Error do
-        parse "generate-loc-drop strings output extra --format apple"
+        parse "generate-loc-drop twine_file output extra --format apple"
       end
     end
 
     def test_format_needed
       assert_raises Twine::Error do
-        parse "generate-loc-drop strings output"
+        parse "generate-loc-drop twine_file output"
       end
     end
   end
 
   class TestConsumeLocDrop < CLITestCase
     def test_command
-      parse "consume-loc-drop #{@strings_file_path} #{@input_path}"
+      parse "consume-loc-drop #{@twine_file_path} #{@input_path}"
 
       assert_equal 'consume-loc-drop', @options[:command]
-      assert_equal @strings_file_path, @options[:strings_file]
+      assert_equal @twine_file_path, @options[:twine_file]
       assert_equal @input_path, @options[:input_path]
     end
 
     def test_missing_parameter
       assert_raises Twine::Error do
-        parse "consume-loc-drop strings"
+        parse "consume-loc-drop twine_file"
       end
     end
 
     def test_extra_parameter
       assert_raises Twine::Error do
-        parse "consume-loc-drop strings input extra"
+        parse "consume-loc-drop twine_file input extra"
       end
     end
   end
 
   class TestParameters < CLITestCase
     def parse_with(parameter)
-      parse 'validate-strings-file input.txt ' + parameter
+      parse 'validate-twine-file input.txt ' + parameter
     end
 
     def test_default_options
       parse_with ''
-      expected = {command: 'validate-strings-file', strings_file: 'input.txt', include: :all}
+      expected = {command: 'validate-twine-file', twine_file: 'input.txt', include: :all}
       assert_equal expected, @options
     end
 
diff --git a/test/test_consume_loc_drop.rb b/test/test_consume_loc_drop.rb
index deab5c0..cfc6d18 100644
--- a/test/test_consume_loc_drop.rb
+++ b/test/test_consume_loc_drop.rb
@@ -11,7 +11,7 @@ class TestConsumeLocDrop < CommandTestCase
 
     @twine_file = build_twine_file 'en', 'es' do
       add_section 'Section' do
-        add_row key1: 'value1'
+        add_definition key1: 'value1'
       end
     end
 
@@ -21,7 +21,7 @@ class TestConsumeLocDrop < CommandTestCase
   def test_consumes_zip_file
     @runner.consume_loc_drop
 
-    assert @twine_file.strings_map['key1'].translations['en'], 'value1-english'
-    assert @twine_file.strings_map['key1'].translations['es'], 'value1-spanish'
+    assert @twine_file.definitions_by_key['key1'].translations['en'], 'value1-english'
+    assert @twine_file.definitions_by_key['key1'].translations['es'], 'value1-spanish'
   end
 end
diff --git a/test/test_consume_string_file.rb b/test/test_consume_localization_file.rb
similarity index 77%
rename from test/test_consume_string_file.rb
rename to test/test_consume_localization_file.rb
index c56781f..f0bdf86 100644
--- a/test/test_consume_string_file.rb
+++ b/test/test_consume_localization_file.rb
@@ -1,6 +1,6 @@
 require 'command_test_case'
 
-class TestConsumeStringFile < CommandTestCase
+class TestConsumeLocalizationFile < CommandTestCase
   def new_runner(language, file)
     options = {}
     options[:output_path] = File.join(@output_dir, file) if file
@@ -8,10 +8,10 @@ class TestConsumeStringFile < CommandTestCase
     FileUtils.touch options[:input_path]
     options[:languages] = language if language
 
-    @strings = Twine::StringsFile.new
-    @strings.language_codes.concat KNOWN_LANGUAGES
+    @twine_file = Twine::TwineFile.new
+    @twine_file.language_codes.concat KNOWN_LANGUAGES
 
-    Twine::Runner.new(options, @strings)
+    Twine::Runner.new(options, @twine_file)
   end
 
   def prepare_mock_read_formatter(formatter_class)
@@ -22,25 +22,25 @@ class TestConsumeStringFile < CommandTestCase
   def test_deducts_android_format_from_output_path
     prepare_mock_read_formatter Twine::Formatters::Android
 
-    new_runner('fr', 'fr.xml').consume_string_file
+    new_runner('fr', 'fr.xml').consume_localization_file
   end
 
   def test_deducts_apple_format_from_output_path
     prepare_mock_read_formatter Twine::Formatters::Apple
 
-    new_runner('fr', 'fr.strings').consume_string_file
+    new_runner('fr', 'fr.strings').consume_localization_file
   end
 
   def test_deducts_jquery_format_from_output_path
     prepare_mock_read_formatter Twine::Formatters::JQuery
 
-    new_runner('fr', 'fr.json').consume_string_file
+    new_runner('fr', 'fr.json').consume_localization_file
   end
 
   def test_deducts_gettext_format_from_output_path
     prepare_mock_read_formatter Twine::Formatters::Gettext
 
-    new_runner('fr', 'fr.po').consume_string_file
+    new_runner('fr', 'fr.po').consume_localization_file
   end
 
   def test_deducts_language_from_input_path
@@ -48,7 +48,7 @@ class TestConsumeStringFile < CommandTestCase
     formatter = prepare_mock_formatter Twine::Formatters::Android
     formatter.expects(:read).with(anything, random_language)
 
-    new_runner(nil, "#{random_language}.xml").consume_string_file
+    new_runner(nil, "#{random_language}.xml").consume_localization_file
   end
 
   class TestEncodings < CommandTestCase
@@ -75,10 +75,10 @@ class TestConsumeStringFile < CommandTestCase
       options[:encoding] = encoding if encoding
       options[:languages] = 'en'
 
-      @strings = Twine::StringsFile.new
-      @strings.language_codes.concat KNOWN_LANGUAGES
+      @twine_file = Twine::TwineFile.new
+      @twine_file.language_codes.concat KNOWN_LANGUAGES
 
-      Twine::Runner.new(options, @strings)
+      Twine::Runner.new(options, @twine_file)
     end
 
     def setup
@@ -88,31 +88,31 @@ class TestConsumeStringFile < CommandTestCase
 
     def test_reads_utf8
       formatter = prepare_mock_formatter DummyFormatter
-      new_runner(fixture_path('enc_utf8.dummy')).consume_string_file
+      new_runner(fixture_path('enc_utf8.dummy')).consume_localization_file
       assert_equal @expected_content, formatter.content
     end
 
     def test_reads_utf16le_bom
       formatter = prepare_mock_formatter DummyFormatter
-      new_runner(fixture_path('enc_utf16le_bom.dummy')).consume_string_file
+      new_runner(fixture_path('enc_utf16le_bom.dummy')).consume_localization_file
       assert_equal @expected_content, formatter.content
     end
 
     def test_reads_utf16be_bom
       formatter = prepare_mock_formatter DummyFormatter
-      new_runner(fixture_path('enc_utf16be_bom.dummy')).consume_string_file
+      new_runner(fixture_path('enc_utf16be_bom.dummy')).consume_localization_file
       assert_equal @expected_content, formatter.content
     end
 
     def test_reads_utf16le
       formatter = prepare_mock_formatter DummyFormatter
-      new_runner(fixture_path('enc_utf16le.dummy'), 'UTF-16LE').consume_string_file
+      new_runner(fixture_path('enc_utf16le.dummy'), 'UTF-16LE').consume_localization_file
       assert_equal @expected_content, formatter.content
     end
 
     def test_reads_utf16be
       formatter = prepare_mock_formatter DummyFormatter
-      new_runner(fixture_path('enc_utf16be.dummy'), 'UTF-16BE').consume_string_file
+      new_runner(fixture_path('enc_utf16be.dummy'), 'UTF-16BE').consume_localization_file
       assert_equal @expected_content, formatter.content
     end
   end
diff --git a/test/test_formatters.rb b/test/test_formatters.rb
index dd363c6..574cbec 100644
--- a/test/test_formatters.rb
+++ b/test/test_formatters.rb
@@ -6,33 +6,33 @@ class FormatterTest < TwineTestCase
 
     @twine_file = build_twine_file 'en' do
       add_section 'Section 1' do
-        add_row key1: 'value1-english', comment: 'comment key1'
-        add_row key2: 'value2-english'
+        add_definition key1: 'value1-english', comment: 'comment key1'
+        add_definition key2: 'value2-english'
       end
 
       add_section 'Section 2' do
-        add_row key3: 'value3-english'
-        add_row key4: 'value4-english', comment: 'comment key4'
+        add_definition key3: 'value3-english'
+        add_definition key4: 'value4-english', comment: 'comment key4'
       end
     end
 
-    @strings = Twine::StringsFile.new
+    @empty_twine_file = Twine::TwineFile.new
     @formatter = formatter_class.new
-    @formatter.strings = @strings
+    @formatter.twine_file = @empty_twine_file
     @formatter.options = { consume_all: true, consume_comments: true }
   end
 
   def assert_translations_read_correctly
     1.upto(4) do |i|
-      assert_equal "value#{i}-english", @strings.strings_map["key#{i}"].translations['en']
+      assert_equal "value#{i}-english", @empty_twine_file.definitions_by_key["key#{i}"].translations['en']
     end
   end
 
   def assert_file_contents_read_correctly
     assert_translations_read_correctly
 
-    assert_equal "comment key1", @strings.strings_map["key1"].comment
-    assert_equal "comment key4", @strings.strings_map["key4"].comment
+    assert_equal "comment key1", @empty_twine_file.definitions_by_key["key1"].comment
+    assert_equal "comment key4", @empty_twine_file.definitions_by_key["key4"].comment
   end
 end
 
@@ -49,27 +49,27 @@ class TestAndroidFormatter < FormatterTest
 
   def test_set_translation_converts_leading_spaces
     @formatter.set_translation_for_key 'key1', 'en', "\u0020value"
-    assert_equal ' value', @strings.strings_map['key1'].translations['en']
+    assert_equal ' value', @empty_twine_file.definitions_by_key['key1'].translations['en']
   end
 
   def test_set_translation_coverts_trailing_spaces
     @formatter.set_translation_for_key 'key1', 'en', "value\u0020\u0020"
-    assert_equal 'value  ', @strings.strings_map['key1'].translations['en']
+    assert_equal 'value  ', @empty_twine_file.definitions_by_key['key1'].translations['en']
   end
 
   def test_set_translation_converts_string_placeholders
     @formatter.set_translation_for_key 'key1', 'en', "value %s"
-    assert_equal 'value %@', @strings.strings_map['key1'].translations['en']
+    assert_equal 'value %@', @empty_twine_file.definitions_by_key['key1'].translations['en']
   end
 
   def test_set_translation_unescapes_at_signs
     @formatter.set_translation_for_key 'key1', 'en', '\@value'
-    assert_equal '@value', @strings.strings_map['key1'].translations['en']
+    assert_equal '@value', @empty_twine_file.definitions_by_key['key1'].translations['en']
   end
 
   def test_format_file
     formatter = Twine::Formatters::Android.new
-    formatter.strings = @twine_file
+    formatter.twine_file = @twine_file
     assert_equal content('formatter_android.xml'), formatter.format_file('en')
   end
 
@@ -139,47 +139,47 @@ class TestAppleFormatter < FormatterTest
 
   def test_reads_quoted_keys
     @formatter.read StringIO.new('"key" = "value"'), 'en'
-    assert_equal 'value', @strings.strings_map['key'].translations['en']
+    assert_equal 'value', @empty_twine_file.definitions_by_key['key'].translations['en']
   end
 
   def test_reads_unquoted_keys
     @formatter.read StringIO.new('key = "value"'), 'en'
-    assert_equal 'value', @strings.strings_map['key'].translations['en']
+    assert_equal 'value', @empty_twine_file.definitions_by_key['key'].translations['en']
   end
 
   def test_ignores_leading_whitespace_before_quoted_keys
     @formatter.read StringIO.new("\t  \"key\" = \"value\""), 'en'
-    assert_equal 'value', @strings.strings_map['key'].translations['en']
+    assert_equal 'value', @empty_twine_file.definitions_by_key['key'].translations['en']
   end
 
   def test_ignores_leading_whitespace_before_unquoted_keys
     @formatter.read StringIO.new("\t  key = \"value\""), 'en'
-    assert_equal 'value', @strings.strings_map['key'].translations['en']
+    assert_equal 'value', @empty_twine_file.definitions_by_key['key'].translations['en']
   end
 
   def test_allows_quotes_in_quoted_keys
     @formatter.read StringIO.new('"ke\"y" = "value"'), 'en'
-    assert_equal 'value', @strings.strings_map['ke"y'].translations['en']
+    assert_equal 'value', @empty_twine_file.definitions_by_key['ke"y'].translations['en']
   end
 
   def test_does_not_allow_quotes_in_quoted_keys
     @formatter.read StringIO.new('ke"y = "value"'), 'en'
-    assert_nil @strings.strings_map['key']
+    assert_nil @empty_twine_file.definitions_by_key['key']
   end
 
   def test_allows_equal_signs_in_quoted_keys
     @formatter.read StringIO.new('"k=ey" = "value"'), 'en'
-    assert_equal 'value', @strings.strings_map['k=ey'].translations['en']
+    assert_equal 'value', @empty_twine_file.definitions_by_key['k=ey'].translations['en']
   end
 
   def test_does_not_allow_equal_signs_in_unquoted_keys
     @formatter.read StringIO.new('k=ey = "value"'), 'en'
-    assert_nil @strings.strings_map['key']
+    assert_nil @empty_twine_file.definitions_by_key['key']
   end
 
   def test_format_file
     formatter = Twine::Formatters::Apple.new
-    formatter.strings = @twine_file
+    formatter.twine_file = @twine_file
     assert_equal content('formatter_apple.strings'), formatter.format_file('en')
   end
 
@@ -210,7 +210,7 @@ class TestJQueryFormatter < FormatterTest
 
   def test_format_file
     formatter = Twine::Formatters::JQuery.new
-    formatter.strings = @twine_file
+    formatter.twine_file = @twine_file
     assert_equal content('formatter_jquery.json'), formatter.format_file('en')
   end
 
@@ -234,12 +234,12 @@ class TestGettextFormatter < FormatterTest
   def test_read_with_multiple_line_value
     @formatter.read content_io('gettext_multiline.po'), 'en'
 
-    assert_equal 'multiline\nstring', @strings.strings_map['key1'].translations['en']
+    assert_equal 'multiline\nstring', @empty_twine_file.definitions_by_key['key1'].translations['en']
   end
 
   def test_format_file
     formatter = Twine::Formatters::Gettext.new
-    formatter.strings = @twine_file
+    formatter.twine_file = @twine_file
     assert_equal content('formatter_gettext.po'), formatter.format_file('en')
   end
 
@@ -260,7 +260,7 @@ class TestTizenFormatter < FormatterTest
 
   def test_format_file
     formatter = Twine::Formatters::Tizen.new
-    formatter.strings = @twine_file
+    formatter.twine_file = @twine_file
     assert_equal content('formatter_tizen.xml'), formatter.format_file('en')
   end
 
@@ -279,7 +279,7 @@ class TestDjangoFormatter < FormatterTest
 
   def test_format_file
     formatter = Twine::Formatters::Django.new
-    formatter.strings = @twine_file
+    formatter.twine_file = @twine_file
     assert_equal content('formatter_django.po'), formatter.format_file('en')
   end
 end
@@ -297,7 +297,7 @@ class TestFlashFormatter < FormatterTest
 
   def test_format_file
     formatter = Twine::Formatters::Flash.new
-    formatter.strings = @twine_file
+    formatter.twine_file = @twine_file
     assert_equal content('formatter_flash.properties'), formatter.format_file('en')
   end
 end
diff --git a/test/test_generate_all_string_files.rb b/test/test_generate_all_localization_files.rb
similarity index 72%
rename from test/test_generate_all_string_files.rb
rename to test/test_generate_all_localization_files.rb
index 97c7ba8..3cda08f 100644
--- a/test/test_generate_all_string_files.rb
+++ b/test/test_generate_all_localization_files.rb
@@ -1,6 +1,6 @@
 require 'command_test_case'
 
-class TestGenerateAllStringFiles < CommandTestCase
+class TestGenerateAllLocalizationFiles < CommandTestCase
   def new_runner(create_folders, twine_file = nil)
     options = {}
     options[:output_path] = @output_dir
@@ -10,7 +10,7 @@ class TestGenerateAllStringFiles < CommandTestCase
     unless twine_file
       twine_file = build_twine_file 'en', 'es' do
         add_section 'Section' do
-          add_row key: 'value'
+          add_definition key: 'value'
         end
       end
     end
@@ -18,51 +18,51 @@ class TestGenerateAllStringFiles < CommandTestCase
     Twine::Runner.new(options, twine_file)
   end
 
-  class TestDoNotCreateFolders < TestGenerateAllStringFiles
+  class TestDoNotCreateFolders < TestGenerateAllLocalizationFiles
     def new_runner(twine_file = nil)
       super(false, twine_file)
     end
 
     def test_fails_if_output_folder_does_not_exist
       assert_raises Twine::Error do
-        new_runner.generate_all_string_files
+        new_runner.generate_all_localization_files
       end
     end
 
     def test_does_not_create_language_folders
       Dir.mkdir File.join @output_dir, 'en.lproj'
-      new_runner.generate_all_string_files
+      new_runner.generate_all_localization_files
       refute File.exists?(File.join(@output_dir, 'es.lproj')), "language folder should not be created"
     end
 
     def test_prints_empty_file_warnings
       Dir.mkdir File.join @output_dir, 'en.lproj'
       empty_twine_file = build_twine_file('en') {}
-      new_runner(empty_twine_file).generate_all_string_files
+      new_runner(empty_twine_file).generate_all_localization_files
       assert_match "Skipping file at path", Twine::stderr.string
     end
   end
 
-  class TestCreateFolders < TestGenerateAllStringFiles
+  class TestCreateFolders < TestGenerateAllLocalizationFiles
     def new_runner(twine_file = nil)
       super(true, twine_file)
     end
 
     def test_creates_output_folder
       FileUtils.remove_entry_secure @output_dir
-      new_runner.generate_all_string_files
+      new_runner.generate_all_localization_files
       assert File.exists? @output_dir
     end
 
     def test_creates_language_folders
-      new_runner.generate_all_string_files
+      new_runner.generate_all_localization_files
       assert File.exists?(File.join(@output_dir, 'en.lproj')), "language folder 'en.lproj' should be created"
       assert File.exists?(File.join(@output_dir, 'es.lproj')), "language folder 'es.lproj' should be created"
     end
 
     def test_prints_empty_file_warnings
       empty_twine_file = build_twine_file('en') {}
-      new_runner(empty_twine_file).generate_all_string_files
+      new_runner(empty_twine_file).generate_all_localization_files
 
       assert_match "Skipping file at path", Twine::stderr.string
     end
@@ -79,23 +79,23 @@ class TestGenerateAllStringFiles < CommandTestCase
 
       twine_file = build_twine_file 'en' do
         add_section 'Section' do
-          add_row key: 'value'
-          add_row key: 'value'
+          add_definition key: 'value'
+          add_definition key: 'value'
         end
       end
 
       Twine::Runner.new(options, twine_file)
     end
 
-    def test_does_not_validate_strings_file
+    def test_does_not_validate_twine_file
       prepare_mock_formatter Twine::Formatters::Android
 
-      new_runner(false).generate_all_string_files
+      new_runner(false).generate_all_localization_files
     end
 
-    def test_validates_strings_file_if_validate
+    def test_validates_twine_file_if_validate
       assert_raises Twine::Error do
-        new_runner(true).generate_all_string_files
+        new_runner(true).generate_all_localization_files
       end
     end
   end
diff --git a/test/test_generate_loc_drop.rb b/test/test_generate_loc_drop.rb
index 4912198..3c7c4a3 100644
--- a/test/test_generate_loc_drop.rb
+++ b/test/test_generate_loc_drop.rb
@@ -9,7 +9,7 @@ class TestGenerateLocDrop < CommandTestCase
     unless twine_file
       twine_file = build_twine_file 'en', 'fr' do
         add_section 'Section' do
-          add_row key: 'value'
+          add_definition key: 'value'
         end
       end
     end
@@ -57,21 +57,21 @@ class TestGenerateLocDrop < CommandTestCase
 
       twine_file = build_twine_file 'en' do
         add_section 'Section' do
-          add_row key: 'value'
-          add_row key: 'value'
+          add_definition key: 'value'
+          add_definition key: 'value'
         end
       end
 
       Twine::Runner.new(options, twine_file)
     end
 
-    def test_does_not_validate_strings_file
+    def test_does_not_validate_twine_file
       prepare_mock_formatter Twine::Formatters::Android
 
       new_runner(false).generate_loc_drop
     end
 
-    def test_validates_strings_file_if_validate
+    def test_validates_twine_file_if_validate
       assert_raises Twine::Error do
         new_runner(true).generate_loc_drop
       end
diff --git a/test/test_generate_string_file.rb b/test/test_generate_localization_file.rb
similarity index 69%
rename from test/test_generate_string_file.rb
rename to test/test_generate_localization_file.rb
index d6d3835..3d338c6 100644
--- a/test/test_generate_string_file.rb
+++ b/test/test_generate_localization_file.rb
@@ -1,15 +1,15 @@
 require 'command_test_case'
 
-class TestGenerateStringFile < CommandTestCase
+class TestGenerateLocalizationFile < CommandTestCase
   def new_runner(language, file)
     options = {}
     options[:output_path] = File.join(@output_dir, file) if file
     options[:languages] = language if language
 
-    strings = Twine::StringsFile.new
-    strings.language_codes.concat KNOWN_LANGUAGES
+    twine_file = Twine::TwineFile.new
+    twine_file.language_codes.concat KNOWN_LANGUAGES
 
-    Twine::Runner.new(options, strings)
+    Twine::Runner.new(options, twine_file)
   end
 
   def prepare_mock_format_file_formatter(formatter_class)
@@ -20,25 +20,25 @@ class TestGenerateStringFile < CommandTestCase
   def test_deducts_android_format_from_output_path
     prepare_mock_format_file_formatter Twine::Formatters::Android
 
-    new_runner('fr', 'fr.xml').generate_string_file
+    new_runner('fr', 'fr.xml').generate_localization_file
   end
 
   def test_deducts_apple_format_from_output_path
     prepare_mock_format_file_formatter Twine::Formatters::Apple
 
-    new_runner('fr', 'fr.strings').generate_string_file
+    new_runner('fr', 'fr.strings').generate_localization_file
   end
 
   def test_deducts_jquery_format_from_output_path
     prepare_mock_format_file_formatter Twine::Formatters::JQuery
 
-    new_runner('fr', 'fr.json').generate_string_file
+    new_runner('fr', 'fr.json').generate_localization_file
   end
 
   def test_deducts_gettext_format_from_output_path
     prepare_mock_format_file_formatter Twine::Formatters::Gettext
 
-    new_runner('fr', 'fr.po').generate_string_file
+    new_runner('fr', 'fr.po').generate_localization_file
   end
 
   def test_deducts_language_from_output_path
@@ -46,7 +46,7 @@ class TestGenerateStringFile < CommandTestCase
     formatter = prepare_mock_formatter Twine::Formatters::Android
     formatter.expects(:format_file).with(random_language).returns(true)
 
-    new_runner(nil, "#{random_language}.xml").generate_string_file
+    new_runner(nil, "#{random_language}.xml").generate_localization_file
   end
 
   def test_returns_error_if_nothing_written
@@ -54,7 +54,7 @@ class TestGenerateStringFile < CommandTestCase
     formatter.expects(:format_file).returns(false)
 
     assert_raises Twine::Error do
-      new_runner('fr', 'fr.xml').generate_string_file
+      new_runner('fr', 'fr.xml').generate_localization_file
     end
   end
 
@@ -68,23 +68,23 @@ class TestGenerateStringFile < CommandTestCase
 
       twine_file = build_twine_file 'en' do
         add_section 'Section' do
-          add_row key: 'value'
-          add_row key: 'value'
+          add_definition key: 'value'
+          add_definition key: 'value'
         end
       end
 
       Twine::Runner.new(options, twine_file)
     end
 
-    def test_does_not_validate_strings_file
+    def test_does_not_validate_twine_file
       prepare_mock_formatter Twine::Formatters::Android
 
-      new_runner(false).generate_string_file
+      new_runner(false).generate_localization_file
     end
 
-    def test_validates_strings_file_if_validate
+    def test_validates_twine_file_if_validate
       assert_raises Twine::Error do
-        new_runner(true).generate_string_file
+        new_runner(true).generate_localization_file
       end
     end
   end
diff --git a/test/test_output_processor.rb b/test/test_output_processor.rb
index 7a6c905..e51a0ad 100644
--- a/test/test_output_processor.rb
+++ b/test/test_output_processor.rb
@@ -4,81 +4,81 @@ class TestOutputProcessor < TwineTestCase
   def setup
     super
 
-    @strings = build_twine_file 'en', 'fr' do
+    @twine_file = build_twine_file 'en', 'fr' do
       add_section 'Section' do
-        add_row key1: 'value1', tags: ['tag1']
-        add_row key2: 'value2', tags: ['tag1', 'tag2']
-        add_row key3: 'value3', tags: ['tag2']
-        add_row key4: { en: 'value4-en', fr: 'value4-fr' }
+        add_definition key1: 'value1', tags: ['tag1']
+        add_definition key2: 'value2', tags: ['tag1', 'tag2']
+        add_definition key3: 'value3', tags: ['tag2']
+        add_definition key4: { en: 'value4-en', fr: 'value4-fr' }
       end
     end
   end
 
   def test_includes_all_keys_by_default
-    processor = Twine::Processors::OutputProcessor.new(@strings, {})
+    processor = Twine::Processors::OutputProcessor.new(@twine_file, {})
     result = processor.process('en')
 
-    assert_equal %w(key1 key2 key3 key4), result.strings_map.keys.sort
+    assert_equal %w(key1 key2 key3 key4), result.definitions_by_key.keys.sort
   end
 
   def test_filter_by_tag
-    processor = Twine::Processors::OutputProcessor.new(@strings, { tags: ['tag1'] })
+    processor = Twine::Processors::OutputProcessor.new(@twine_file, { tags: ['tag1'] })
     result = processor.process('en')
 
-    assert_equal %w(key1 key2), result.strings_map.keys.sort
+    assert_equal %w(key1 key2), result.definitions_by_key.keys.sort
   end
 
   def test_filter_by_multiple_tags
-    processor = Twine::Processors::OutputProcessor.new(@strings, { tags: ['tag1', 'tag2'] })
+    processor = Twine::Processors::OutputProcessor.new(@twine_file, { tags: ['tag1', 'tag2'] })
     result = processor.process('en')
 
-    assert_equal %w(key1 key2 key3), result.strings_map.keys.sort
+    assert_equal %w(key1 key2 key3), result.definitions_by_key.keys.sort
   end
 
   def test_filter_untagged
-    processor = Twine::Processors::OutputProcessor.new(@strings, { tags: ['tag1'], untagged: true })
+    processor = Twine::Processors::OutputProcessor.new(@twine_file, { tags: ['tag1'], untagged: true })
     result = processor.process('en')
 
-    assert_equal %w(key1 key2 key4), result.strings_map.keys.sort
+    assert_equal %w(key1 key2 key4), result.definitions_by_key.keys.sort
   end
 
   def test_include_translated
-    processor = Twine::Processors::OutputProcessor.new(@strings, { include: :translated })
+    processor = Twine::Processors::OutputProcessor.new(@twine_file, { include: :translated })
     result = processor.process('fr')
 
-    assert_equal %w(key4), result.strings_map.keys.sort
+    assert_equal %w(key4), result.definitions_by_key.keys.sort
   end
 
   def test_include_untranslated
-    processor = Twine::Processors::OutputProcessor.new(@strings, { include: :untranslated })
+    processor = Twine::Processors::OutputProcessor.new(@twine_file, { include: :untranslated })
     result = processor.process('fr')
 
-    assert_equal %w(key1 key2 key3), result.strings_map.keys.sort
+    assert_equal %w(key1 key2 key3), result.definitions_by_key.keys.sort
   end
 
   class TranslationFallback < TwineTestCase
     def setup
       super
 
-      @strings = build_twine_file 'en', 'fr', 'de' do
+      @twine_file = build_twine_file 'en', 'fr', 'de' do
         add_section 'Section' do
-          add_row key1: { en: 'value1-en', fr: 'value1-fr' }
+          add_definition key1: { en: 'value1-en', fr: 'value1-fr' }
         end
       end
     end
 
     def test_fallback_to_default_language
-      processor = Twine::Processors::OutputProcessor.new(@strings, {})
+      processor = Twine::Processors::OutputProcessor.new(@twine_file, {})
       result = processor.process('de')
       
-      assert_equal 'value1-en', result.strings_map['key1'].translations['de']
+      assert_equal 'value1-en', result.definitions_by_key['key1'].translations['de']
     end
 
     def test_fallback_to_developer_language
-      processor = Twine::Processors::OutputProcessor.new(@strings, {developer_language: 'fr'})
+      processor = Twine::Processors::OutputProcessor.new(@twine_file, {developer_language: 'fr'})
       result = processor.process('de')
       
-      assert_equal 'value1-fr', result.strings_map['key1'].translations['de']
+      assert_equal 'value1-fr', result.definitions_by_key['key1'].translations['de']
     end
   end
 
diff --git a/test/test_strings_file.rb b/test/test_strings_file.rb
deleted file mode 100644
index be51976..0000000
--- a/test/test_strings_file.rb
+++ /dev/null
@@ -1,58 +0,0 @@
-require 'twine_test_case'
-
-class TestStringsFile < TwineTestCase
-  class Reading < TwineTestCase
-    def setup
-      super
-
-      @strings = Twine::StringsFile.new
-      @strings.read fixture_path('twine_accent_values.txt')
-    end
-
-    def test_reading_keeps_leading_accent
-      assert_equal '`value', @strings.strings_map['value_with_leading_accent'].translations['en']
-    end
-
-    def test_reading_keeps_trailing_accent
-      assert_equal 'value`', @strings.strings_map['value_with_trailing_accent'].translations['en']
-    end
-
-    def test_reading_keeps_leading_space
-      assert_equal ' value', @strings.strings_map['value_with_leading_space'].translations['en']
-    end
-
-    def test_reading_keeps_trailing_space
-      assert_equal 'value ', @strings.strings_map['value_with_trailing_space'].translations['en']
-    end
-
-    def test_reading_keeps_wrapping_spaces
-      assert_equal ' value ', @strings.strings_map['value_wrapped_by_spaces'].translations['en']
-    end
-
-    def test_reading_keeps_wrapping_accents
-      assert_equal '`value`', @strings.strings_map['value_wrapped_by_accents'].translations['en']
-    end
-  end
-
-  class Writing < TwineTestCase
-
-    def test_accent_wrapping
-      @strings = build_twine_file 'en' do
-        add_section 'Section' do
-          add_row value_with_leading_accent: '`value'
-          add_row value_with_trailing_accent: 'value`'
-          add_row value_with_leading_space: ' value'
-          add_row value_with_trailing_space: 'value '
-          add_row value_wrapped_by_spaces: ' value '
-          add_row value_wrapped_by_accents: '`value`'
-        end
-      end
-
-      @strings.write @output_path
-
-      assert_equal content('twine_accent_values.txt'), File.read(@output_path)
-    end
-
-  end
-
-end
diff --git a/test/test_strings_row.rb b/test/test_strings_row.rb
deleted file mode 100644
index b477483..0000000
--- a/test/test_strings_row.rb
+++ /dev/null
@@ -1,47 +0,0 @@
-require 'twine_test_case'
-
-class TestStringsRow < TwineTestCase
-  def setup
-    super
-
-    @reference = Twine::StringsRow.new 'reference-key'
-    @reference.comment = 'reference comment'
-    @reference.tags = ['ref1']
-    @reference.translations['en'] = 'ref-value'
-
-    @row = Twine::StringsRow.new 'key'
-    @row.reference_key = @reference.key
-    @row.reference = @reference
-  end
-
-  def test_reference_comment_used
-    assert_equal 'reference comment', @row.comment
-  end
-
-  def test_reference_comment_override
-    @row.comment = 'row comment'
-
-    assert_equal 'row comment', @row.comment
-  end
-
-  def test_reference_tags_used
-    assert @row.matches_tags?(['ref1'], false)
-  end
-
-  def test_reference_tags_override
-    @row.tags = ['tag1']
-
-    refute @row.matches_tags?(['ref1'], false)
-    assert @row.matches_tags?(['tag1'], false)
-  end
-
-  def test_reference_translation_used
-    assert_equal 'ref-value', @row.translated_string_for_lang('en')
-  end
-
-  def test_reference_translation_override
-    @row.translations['en'] = 'value'
-
-    assert_equal 'value', @row.translated_string_for_lang('en')
-  end
-end
diff --git a/test/test_twine_definition.rb b/test/test_twine_definition.rb
new file mode 100644
index 0000000..e25a900
--- /dev/null
+++ b/test/test_twine_definition.rb
@@ -0,0 +1,47 @@
+require 'twine_test_case'
+
+class TestTwineDefinition < TwineTestCase
+  def setup
+    super
+
+    @reference = Twine::TwineDefinition.new 'reference-key'
+    @reference.comment = 'reference comment'
+    @reference.tags = ['ref1']
+    @reference.translations['en'] = 'ref-value'
+
+    @definition = Twine::TwineDefinition.new 'key'
+    @definition.reference_key = @reference.key
+    @definition.reference = @reference
+  end
+
+  def test_reference_comment_used
+    assert_equal 'reference comment', @definition.comment
+  end
+
+  def test_reference_comment_override
+    @definition.comment = 'definition comment'
+
+    assert_equal 'definition comment', @definition.comment
+  end
+
+  def test_reference_tags_used
+    assert @definition.matches_tags?(['ref1'], false)
+  end
+
+  def test_reference_tags_override
+    @definition.tags = ['tag1']
+
+    refute @definition.matches_tags?(['ref1'], false)
+    assert @definition.matches_tags?(['tag1'], false)
+  end
+
+  def test_reference_translation_used
+    assert_equal 'ref-value', @definition.translation_for_lang('en')
+  end
+
+  def test_reference_translation_override
+    @definition.translations['en'] = 'value'
+
+    assert_equal 'value', @definition.translation_for_lang('en')
+  end
+end
diff --git a/test/test_twine_file.rb b/test/test_twine_file.rb
new file mode 100644
index 0000000..65057e5
--- /dev/null
+++ b/test/test_twine_file.rb
@@ -0,0 +1,58 @@
+require 'twine_test_case'
+
+class TestTwineFile < TwineTestCase
+  class Reading < TwineTestCase
+    def setup
+      super
+
+      @twine_file = Twine::TwineFile.new
+      @twine_file.read fixture_path('twine_accent_values.txt')
+    end
+
+    def test_reading_keeps_leading_accent
+      assert_equal '`value', @twine_file.definitions_by_key['value_with_leading_accent'].translations['en']
+    end
+
+    def test_reading_keeps_trailing_accent
+      assert_equal 'value`', @twine_file.definitions_by_key['value_with_trailing_accent'].translations['en']
+    end
+
+    def test_reading_keeps_leading_space
+      assert_equal ' value', @twine_file.definitions_by_key['value_with_leading_space'].translations['en']
+    end
+
+    def test_reading_keeps_trailing_space
+      assert_equal 'value ', @twine_file.definitions_by_key['value_with_trailing_space'].translations['en']
+    end
+
+    def test_reading_keeps_wrapping_spaces
+      assert_equal ' value ', @twine_file.definitions_by_key['value_wrapped_by_spaces'].translations['en']
+    end
+
+    def test_reading_keeps_wrapping_accents
+      assert_equal '`value`', @twine_file.definitions_by_key['value_wrapped_by_accents'].translations['en']
+    end
+  end
+
+  class Writing < TwineTestCase
+
+    def test_accent_wrapping
+      @twine_file = build_twine_file 'en' do
+        add_section 'Section' do
+          add_definition value_with_leading_accent: '`value'
+          add_definition value_with_trailing_accent: 'value`'
+          add_definition value_with_leading_space: ' value'
+          add_definition value_with_trailing_space: 'value '
+          add_definition value_wrapped_by_spaces: ' value '
+          add_definition value_wrapped_by_accents: '`value`'
+        end
+      end
+
+      @twine_file.write @output_path
+
+      assert_equal content('twine_accent_values.txt'), File.read(@output_path)
+    end
+
+  end
+
+end
diff --git a/test/test_validate_strings_file.rb b/test/test_validate_strings_file.rb
deleted file mode 100644
index c414e75..0000000
--- a/test/test_validate_strings_file.rb
+++ /dev/null
@@ -1,61 +0,0 @@
-# encoding: utf-8
-
-require 'command_test_case'
-
-class TestValidateStringsFile < CommandTestCase
-  def setup
-    super
-    @options = { strings_file: 'input.txt' }
-
-    @twine_file = build_twine_file 'en' do
-      add_section 'Section 1' do
-        add_row key1: 'value1', tags: ['tag1']
-        add_row key2: 'value2', tags: ['tag1']
-      end
-
-      add_section 'Section 2' do
-        add_row key3: 'value3', tags: ['tag1', 'tag2']
-        add_row key4: 'value4', tags: ['tag2']
-      end
-    end
-  end
-
-  def random_row
-    @twine_file.strings_map[@twine_file.strings_map.keys.sample]
-  end
-
-  def test_recognizes_valid_file
-    Twine::Runner.new(@options, @twine_file).validate_strings_file
-    assert_equal "input.txt is valid.\n", Twine::stdout.string
-  end
-
-  def test_reports_duplicate_keys
-    @twine_file.sections[0].rows << random_row
-
-    assert_raises Twine::Error do
-      Twine::Runner.new(@options, @twine_file).validate_strings_file
-    end
-  end
-
-  def test_reports_invalid_characters_in_keys
-    random_row.key[0] = "!?;:,^`´'\"\\|/(){}[]~-+*=#$%".chars.to_a.sample
-
-    assert_raises Twine::Error do
-      Twine::Runner.new(@options, @twine_file).validate_strings_file
-    end
-  end
-
-  def test_does_not_reports_missing_tags_by_default
-    random_row.tags.clear
-
-    Twine::Runner.new(@options, @twine_file).validate_strings_file
-  end
-
-  def test_reports_missing_tags
-    random_row.tags.clear
-
-    assert_raises Twine::Error do
-      Twine::Runner.new(@options.merge(pedantic: true), @twine_file).validate_strings_file
-    end
-  end
-end
diff --git a/test/test_validate_twine_file.rb b/test/test_validate_twine_file.rb
new file mode 100644
index 0000000..65270f0
--- /dev/null
+++ b/test/test_validate_twine_file.rb
@@ -0,0 +1,61 @@
+# encoding: utf-8
+
+require 'command_test_case'
+
+class TestValidateTwineFile < CommandTestCase
+  def setup
+    super
+    @options = { twine_file: 'input.txt' }
+
+    @twine_file = build_twine_file 'en' do
+      add_section 'Section 1' do
+        add_definition key1: 'value1', tags: ['tag1']
+        add_definition key2: 'value2', tags: ['tag1']
+      end
+
+      add_section 'Section 2' do
+        add_definition key3: 'value3', tags: ['tag1', 'tag2']
+        add_definition key4: 'value4', tags: ['tag2']
+      end
+    end
+  end
+
+  def random_definition
+    @twine_file.definitions_by_key[@twine_file.definitions_by_key.keys.sample]
+  end
+
+  def test_recognizes_valid_file
+    Twine::Runner.new(@options, @twine_file).validate_twine_file
+    assert_equal "input.txt is valid.\n", Twine::stdout.string
+  end
+
+  def test_reports_duplicate_keys
+    @twine_file.sections[0].definitions << random_definition
+
+    assert_raises Twine::Error do
+      Twine::Runner.new(@options, @twine_file).validate_twine_file
+    end
+  end
+
+  def test_reports_invalid_characters_in_keys
+    random_definition.key[0] = "!?;:,^`´'\"\\|/(){}[]~-+*=#$%".chars.to_a.sample
+
+    assert_raises Twine::Error do
+      Twine::Runner.new(@options, @twine_file).validate_twine_file
+    end
+  end
+
+  def test_does_not_reports_missing_tags_by_default
+    random_definition.tags.clear
+
+    Twine::Runner.new(@options, @twine_file).validate_twine_file
+  end
+
+  def test_reports_missing_tags
+    random_definition.tags.clear
+
+    assert_raises Twine::Error do
+      Twine::Runner.new(@options.merge(pedantic: true), @twine_file).validate_twine_file
+    end
+  end
+end
diff --git a/test/twine_file_dsl.rb b/test/twine_file_dsl.rb
index 5eba9b9..8b50624 100644
--- a/test/twine_file_dsl.rb
+++ b/test/twine_file_dsl.rb
@@ -1,6 +1,6 @@
 module TwineFileDSL
   def build_twine_file(*languages)
-    @currently_built_twine_file = Twine::StringsFile.new
+    @currently_built_twine_file = Twine::TwineFile.new
     @currently_built_twine_file.language_codes.concat languages
     yield
     result = @currently_built_twine_file
@@ -10,37 +10,37 @@ module TwineFileDSL
 
   def add_section(name)
     return unless @currently_built_twine_file
-    @currently_built_twine_file_section = Twine::StringsSection.new name
+    @currently_built_twine_file_section = Twine::TwineSection.new name
     @currently_built_twine_file.sections << @currently_built_twine_file_section
     yield
     @currently_built_twine_file_section = nil
   end
 
-  def add_row(parameters)
+  def add_definition(parameters)
     return unless @currently_built_twine_file
     return unless @currently_built_twine_file_section
 
     # this relies on Ruby preserving the order of hash elements
     key, value = parameters.first
-    row = Twine::StringsRow.new(key.to_s)
+    definition = Twine::TwineDefinition.new(key.to_s)
     if value.is_a? Hash
       value.each do |language, translation|
-        row.translations[language.to_s] = translation
+        definition.translations[language.to_s] = translation
       end
     elsif !value.is_a? Symbol
       language = @currently_built_twine_file.language_codes.first
-      row.translations[language] = value
+      definition.translations[language] = value
     end
 
-    row.comment = parameters[:comment] if parameters[:comment]
-    row.tags = parameters[:tags] if parameters[:tags]
+    definition.comment = parameters[:comment] if parameters[:comment]
+    definition.tags = parameters[:tags] if parameters[:tags]
     if parameters[:ref] || value.is_a?(Symbol)
       reference_key = (parameters[:ref] || value).to_s
-      row.reference_key = reference_key
-      row.reference = @currently_built_twine_file.strings_map[reference_key]
+      definition.reference_key = reference_key
+      definition.reference = @currently_built_twine_file.definitions_by_key[reference_key]
     end
 
-    @currently_built_twine_file_section.rows << row
-    @currently_built_twine_file.strings_map[row.key] = row
+    @currently_built_twine_file_section.definitions << definition
+    @currently_built_twine_file.definitions_by_key[definition.key] = definition
   end
 end
diff --git a/twine.gemspec b/twine.gemspec
index 975cfb9..98bc26a 100644
--- a/twine.gemspec
+++ b/twine.gemspec
@@ -5,7 +5,7 @@ Gem::Specification.new do |s|
   s.name         = "twine"
   s.version      = Twine::VERSION
   s.date         = Time.now.strftime('%Y-%m-%d')
-  s.summary      = "Manage strings and their translations for your iOS and Android projects."
+  s.summary      = "Manage strings and their translations for your iOS, Android and other projects."
   s.homepage     = "https://github.com/mobiata/twine"
   s.email        = "twine@mobiata.com"
   s.authors      = [ "Sebastian Celis" ]
@@ -31,4 +31,6 @@ Gem::Specification.new do |s|
 
   It is geared toward Mac OS X, iOS, and Android developers.
 desc
+
+  s.post_install_message = "Twine command names have changed! Please check the documentation for their new names."
 end