why rails is internationalization framework ?

what is internationalization framework ?
why rails is internationalization framework ?
what are the advance in rails 2.2.0 over rails (< 2.1.1)

what is internationalization framework ?
why rails is internationalization framework ?

http://www.artweb-design.de/2008/7/18/the-ruby-on-rails-i18n-core-api
covers rails 2.2's l18n features.

Fred