2.1 Authentication Services Overview
The Authentication Services protocols include protocols that provide account authentication, authorization, access control, policy enforcement, data-packets usage accounting, and data-packet auditing services between a client and a server.
These protocols can be used to provide:
Authentication services substantially similar to how a Windows Server domain controller provides authentication services to Windows clients and users.
Windows logon and security subsystems services for Windows clients.
Remote administration functionality to support the authentication services listed above.