All definition of language files are saved in below location:
/development/definition/language/
Each definition file has two part Base and Lang.
Base part contain Language code and Title. We use code to register code in session to set a particular language. "default" is set a default language in system. See below example:
<base>
<code>default</code>
<title>US English</title>
</base>
Langs
Langs contain each language phase. Each phase has two part Key and value. Key is used to identify and display value. See below example:
<langs>
<lang>
<key>_HOME</key>
<val>Home</val>
</lang>
</langs>
Each language definition must contain both Base and language together. See below example:
<?xml version="1.0"?>
<Language>
<base>
<code>lipsum</code>
<title>Dummy Language</title>
</base>
<langs>
<lang>
<key>Home</key>
<val>Lorem ipsum</val>
</lang>
</langs>
</Language>