Required for users who want to log on to a network and access its resources. Credentials, which are formed by combining a users username and password, identify users so that they can be authenticated by the network security provider.
Credentials for access to one network do not guarantee access to another network.
In networks based on Microsoft Windows NT and Windows 2000, computers called domain controllers are responsible for authentication of users credentials.
In addition, trust relationships can be established between Windows NT domains to allow users credentials to be authenticated from anywhere in the enterprise. Windows NT and Windows 2000 support single-user logon, which allows a user to use a single set of credentials for accessing resources anywhere on a network.