Vocabularies contain the words the user wants to use to communicate. They are highly personal. Words are organised into categories and subcategories.
Some categories may contain general words, that are the same for all users. For example, many users will want to refer to things found inside the house, or things in the street.
Other categories will contain personal words. Imagine a user wants to mention family members, or specific personal belongings. Special categories, created by an editor, can refer to these personal items.
Simply by selecting categories, subcategories and words, the user can communicate.