The provider model in ASP.NET 2.0 provides extensibility points for developers to plug their own implementation of a feature into the runtime. Both the membership and role features in ASP.NET 2.0 follow the provider pattern by specifying an interface, or contract. The provider model begins with the abstract class ProviderBase.
ASP.NET 2.0's provider model enables developers to extend its functionality by implementing their own versions of features.  The membership and role features in ASP.NET 2.0 utilize a contract-based approach, defining an interface that outlines how these features should function. The ProviderBase class serves as the foundation for creating providers.