Drupal user interface text (and the text displayed by most contributed modules) is written in English. Translation moderators review the translations written by Translators so they can be displayed in place of the English text when the user selects another language. Translation moderators also review versions of Drupal and contributed module documentation in other languages.
When a Translation group manager approves you as a translation moderator, you are given the "translation community moderator" role within the given language group on Localize.drupal.org. (See More granular group permission control deployed for more information about permissions.)
Translation moderators extend the usability of Drupal to a worldwide audience. They assure the quality of translated text. Providing Drupal that is usable by speakers of non-English languages is key to Principle 2: Build software that everyone can use.
Ensuring that translations made by others are accurate and consistent.
After you have been translating for a while, and have had translations approved, ask your language's group leader to make you a Reviewer for your language on localize.drupal.org.
