Provider design pattern at a glance

In a nutshell, the provider model is a design pattern largely used by Microsoft components for allowing an application to make use and choose from multiple implementations of a given contract based on the settings of a configuration file. So, for instance, management of user membership or roles are usually carried out by means of classes based on this pattern (see MemberShipProvider or RoleProvider classes). This way, the application can choose the default provider for dealing with membership or roles, add or remove providers, etc. in a declarative way. It brings a lot of benefits for developers as they can plug new components easily without refactoring code.