Some of them will be displayed in the data model designer, and some will be virtual - that is, you will not see them in the designer, but you can use them, for example, when setting up business processes.
The automatically generated data models add their own blocks of business processes. However, these blocks may differ from the standard ones added by the custom models you create in the AppMaster.io Studio Data Designer.
Detailed information about a particular model can be found on its page in the List of generated models section.