Windows Authentication
The authentication process facilitated by a Windows server allows users logging on to the network to identify themselves to the Active Directory, and subsequently to access all the network resources to which they have permissions. This means that it is necessary to log on only once to access all the resources on the network. The nature of directory services means that other applications, such as a Web server, can interface with the directory and use the same authentication information.
In addition to the standard authentication mechanism of usernames and passwords, Windows server platforms also support other authentication systems such as smartcards and biometrics. Implementation of these methods requires additional hardware and software.