The Users Groups enable you to reunite several users created on your account and give them the same accesses in one time. This can reduce the time spent in giving access to a multitude of users.
Click on the small wheel on the right of the top-menu then on Groups to manage them.
Create a new role
Modify or delete a User group
Click on the pen icon next to the user group you want to edit. As soon as you Save the changes, all the users with the profile will be impacted by the changes. Click on the no entry sign icon next to the profile to delete a users group. All the users will be impacted by this change.