There are three different roles: Admin, Power User, and Learner.
Admin: The user role that has the most permissions. Administrators have complete control over the platform. They can add and remove users, material and assessments, edit user information, change learner grades, disable logins, create courses, view reports, and much more. Given how much power an admin has over a platform, it is extremely important that you only give admin privileges to people who you trust.
Power Users: A custom role that lets you choose specific actions that a user can perform, as well as where they can apply those permissions.
Learner: The role with the least amount of permissions. They can only do the most basic of functions - access courses and the content you make available in the resource center.