In ASP.NET,Role management helps you manage authorization, which enables you to specify the resources that users in your application are allowed to access.Role management lets you treat groups of users as a unit by assigning users to roles such as manager, sales, member, and so on.

After you have established roles, you can create access rules in your application.A typical use is to then create a set of pages that you want to restrict to certain users.Often you isolate these restricted pages in a folder by themselves.Then you can establish rules that grant and deny access to restricted folders.For example, you can configure the site so that members or managers have access to the pages in the restricted folder and all other users are denied access.If an unauthorized user tries to view a restricted page, the user either sees an error or is redirected to a page that you specify.

If you want to insert, update and delete roles, ASP.NET contains powerful role management API. Using those API, you can create,delete role, add user to role,find user in role ect.Specific usage, please read RoleProvider Class

If you want to enable role management for your asp.net application,you need to do the following things:

1. Configure Role Store

2. Configure Role Provider in Web.config

3. Create and Assign Roles

4. Perform Role-Based Authorization

For more details,please read Use Role Manager in ASP.NET 2.0