Roles and Permissions
A role is a way to configure permissions for users based on the kinds of tasks they perform. Roles group users with the same permissions under a unique name. Permissions assigned to roles may not be customized. Roles defined in the workspace allow users to be coordinators, author, or readers. Only a coordinator at the workspace level can assign users to roles for the entire workspace or for any folder in the workspace. In the workspace, users can be readers, authors, or coordinators. By default, users are assigned the role of reader.
Another type of role is an approver. An approver is not a role in the same way that reader, author, and coordinator are roles. Approvers are associated with specific tasks on a per-folder basis. Approvers are assigned only to enhanced folders, because standard folders do not support an approval process. Coordinators on a specific folder are responsible for designating the approvers for their folders.
SharePoint Portal Server stores role memberships with individual folders, rather than in a directory service or in the server's security database. Each folder can contain a different set of users and groups for each role.