Language Collections allow locales to be grouped together for the maintenance and configuration of multiple locales simultaneously.
Language Collections can be used in the Translation Tools interface to translate multiple locales at once. Language collections can be selected on AutoResponder Templates to allow update all locales in the collection at the same time.
Adding a locale to an existing collection used on an AutoResponder will automatically add a template for that locale.
Once you create a Language Collection, you can use it in the Translations to translate the same item for all of the locales within that collection.
Likewise, you can use the Language Collection when creating new Autoresponders. This can speed up the process if you use the same language across multiple countries.