User roles are structures that group the privileges that a certain user group should have. For example, the Superuser role is expected to have most of the capabilities, while ReadOnlyUsers having only viewing claims.
From the User Roles tab, which is one of the sub-tabs of the Users tab, you can view and edit existing roles, add new roles, define privileges, and perform the deletion. You can manage users without having to create separate roles for minor changes, as privileges can be defined independently of roles.