Till date, there were two types of Gnome users, administrators who had special privileges over others and users with standard privileges. Future versions of Gnome may support more account groups, as clear from the below picture.

Apart from Standard and Administrator accounts, custom account types like Teacher, Student and Manager are available. Ofcourse, you can also add your custom account types and grant them privileges according to your choice. The last menu option is Manage.. that will allow you to configure all this.

Gnome developer, Rudolfs Mazurs is currently working on the Manage feature which would be written in Vala. Keep an eye on this space for more Gnome updates.