There are four possible roles: Admin, Manager, Issuer, and Compensation. A user can be assigned to as many roles as they need or none at all. If a user doesn't have a role, they are either a regular user or the account owner.

The Admin role gives access to all features and has the same permissions as the agent/account owner. You would only want to assign this to administrative personnel.  This should be used most sparingly. 

The manager role gives greater access and permissions to a regular user to help give greater support and manage team members. For example, a manager can: Issue Sales, access all reports, edit, add, or remove marketing sources. A manager cannot: Add/Remove/Edit other user profiles, assign goals or scripts, or access customization (i.e. Goals, Products, Actions, and Categories)

The Issuer role gives a regular user the ability to issue policies via the Policy Finder.

The Compensation role gives a regular user access to view/run compensation for all team members. This contains financial information for all users, so it should be assigned sparingly.