ASP.NET membership gives you a built-in way to validate and store user credentials.
ASP.NET Membership works on top of forms-authentication and gives you:
- Ability to create and store users and their passwords with little or no code.
- Out-of-the-box support for changing, resetting, retrieving and encrypting passwords.
- Choice of two storage locations - SQL Server and Active Directory.
- Custom providers can be created to store users in custom stores
Resources
MSDN - Introduction to Membership
4guysfromrolla - Examining ASP.NET's Membership, Roles, and Profile