Customer Groups entity in Data Model?

Hi,

I'm hoping someone can help me with this.

In the Data Model, there are entities linking Customer, Contact and User to Groups.

But where would I find the details of a Group - I am expecting to see an Entity that has links those Groups IDs to a Group name and other Group information.

I can't see it in the Data Model of Entities.

Thanks for any pointers.

Kind regards

Graham