The WinNT schema defines the set of ADSI objects and their class hierarchy for a Windows NT 4.0 network. The ADSI Objects of WinNT include User, Computer, Domain, Group, Resource, Session, Service, and others. The WinNT Object Class Hierarchy section that follows discusses the hierarchical relationships among these objects.
Each object implements a set of ADSI interfaces. However, of an implemented interface, not all properties and methods are supported. WinNT Schema's Mandatory and Optional Properties lists those properties supported by the WinNT object classes.