This diagram illustrates how the translations tables work in the database. 

This is very similar to the way Permissions work. 

• The Organisation table stores the translation group names that are given to a user
• The TranslationCollection table holds the different translation groups e.g. "Default", "UK", "Dutch", "MyOrg"
• The OrganisationTranslation table holds which Translation Collections are used for an Organisation and in what order e.g. a Belgian entry could hold the Default collection to ensure they have at least the core labels. Above this is the standard Dutch collection with a standard naming for all labels but in their own collection e.g. MyOrg, this would hold specific translations used by that organisation if they preferred some other labels than the standard Dutch ones. 
• The Translations table holds all the "raw" translated labels with each of them applied to a Translation Collection record.