Question

Just going to start making a web application and was wondering which was better, or at least what are the main differences between them (as it probably matters what I am using them for)?

• Windows Authentication
• Passport Authentication
• Form Authentication

Answer 1

I would say it greatly depends on what your web app will be doing, as each one has its place. Here is some brief details about each one.

Windows authentication enables you to identify users without creating a custom page.
Credentials are stored in the Web server s local user database or an Active Directory domain. Once identified you can use the user s credentials to gain access to resources that are protected by Windows authorization.

Forms authentication enables you to identify users with a custom database such as an ASP.NET membership database. Alternatively you can implement your own custom database. Once authenticated
you can reference the roles the user is in to restrict access to portions of your Web site.

Passport authentication relies on a centralized service provided by Microsoft. Passport authentication identifies a user with using his or her e-mail address and a password and a single Passport account can be used with many different Web sites.
Passport authentication is primarily used for public Web sites with thousands of users.

Anonymous authentication does not require the user to provide credentials.

http://msdn.microsoft.com/en-us/library/eeyk640h.aspx – ASP.NET Authentication further details on forms and window authentication

Edit
Rushyo link is better: http://msdn.microsoft.com/en-us/library/ee817643.aspx