What are the types of authentication in ASP .NET?

Authentication is the process of obtaining identification credentials such as name and password from a user and validating those credentials against some authority. If the credentials are valid, the entity that submitted the credentials is considered an authenticated identity. Once an identity has been authenticated, the authorization process determines whether that identity has access to a given resource.

ASP.NET implements authentication through authentication providers, the code modules that contain the code necessary to authenticate the requestor’s credentials.

1. Windows Authentication:
This is the default authentication in ASP .NET. Windows Authentication is implemented in ASP.NET using the WindowsAuthenticationModule module. The module constructs a WindowsIdentity based on the credentials supplied by IIS and sets the identity as the current User property value for the application.

2. Forms Authentication
Forms authentication enables you to authenticate the user name and password of your users using a login form that you create. Unauthenticated requests are redirected to a login page, where the user provides credentials and submits the form.

3. Windows Live Authentication:
The Windows Live™ ID service (formerly known as the Passport Network) is the identity and authentication system provided by Windows Live. More than 380 million users have credentials that work with Windows Live ID.