Agent Roles is a feature that allows administrators to manage permissions for large groups of agents more efficiently. 

1. Go to Global Settings > People > Roles.
2. Enable Agent Roles. once enabled you will find two default groups: Site Administrators & All Agents.
   
3. To create a new role click New Agent Role.
   
4. Name your role and assign/remove agents.
   
5. Save.

For more information on configuring agent permissions within groups click here.