Documentation for Crowd 2.0.x. Documentation for other versions of Crowd is available too.
Roles are not often used in Crowd. Correctly speaking a role is a collection of permissions, while a group is a collection of users. Currently in Crowd, roles are not clearly defined and are not used much.
Crowd's role-based access control could be enhanced
At present, the implementation of roles in Crowd is identical to the implementation of groups. Additional development work would be needed to differentiate the functionality of roles from groups. If you would like to help us to design better role-based access control, please add a comment to the improvement request CWD-931, letting us know how you would like to see it work.
Viewing your Group Membership
Introduction to Crowd
Crowd User Guide