Classic authentication supports NT authentication types like:
Kerberos authentication : is a computer network authentication protocol which works on the basis of "tickets" to allow nodes communicating over a non-secure network to prove their identity to one another in a secure manner. Kerberos Authentication Benefits Delegated authentication,Interoperability and Mutual authentication.
NTLM (NT LAN Manager) authentication : is the authentication protocol used on networks that include systems running the Windows operating system and on stand-alone systems.
Basic authentication : is a method for an HTTP user agent to provide a user name and password when making a request.
Digest authentication: is a standards-based authentication protocol that provides for authentication, between Windows operating environments and operating environments other than Windows, over the Internet. It is described in RFC 2617. Windows Server 2003 implements Digest Authentication as a simple authentication and security layer (SASL) mechanism that is used primarily for LDAP authentication, as described in RFC 2831. SASL is method for adding authentication support to connection-based protocols.and it is offers single sign-on only to a single Web URL protection space. If users navigate to a different Web site, or even to a different server in the same site, they will usually be prompted to enter credentials again.
anonymous authentication : gives users access to the public areas of your Web or FTP site without prompting them for a user name or password. By default, the IUSR_computername account is used to allow anonymous access.
Claims-based authentication : uses claims identities against a against a trusted identity provider.