As an Administrator, you have the ability to control settings at an enterprise, group, department, or user level.
As a Group Administrator, you have the ability to designate other group or department administrators. All group administrators will have the same access and feature privileges you do: they'll be able to add, edit, and delete other group administrators, as well as manage the group and its users.
Department Administrators can manage users within the department but are not able to add, delete, or modify other administrator accounts.
All administrators also have access to users' privileges.