When you're working with different kinds of teams, such as webcare, and content managers, you can create user groups for these teams. These groups can be limited in access to channels and brands, but can also be given certain privileges like that's possible with users. User groups can be edited after they're created.
You can add users to user groups when adding a new user or by editing a user (down the list under 'Access control').
When you choose new group you can create a new one. Here you can choose the rights you want for a certain user or mutiple users.