Object model discusses the relationship between Active Directory objects and directory service objects, and introduces the Active Directory objects and dependent objects that compose the Active Directory object model.
Interfaces discusses the suggested interfaces for all Active Directory objects, as well as conventions for custom interfaces.
Active Directory objects explains how to obtain an interface pointer on an Active Directory component object. The mandatory interfaces for Active Directory objects are detailed, as are conventions for custom interfaces.
Dependent objects discusses the collection, security manipulation, stream, and enumerator dependent objects.
Object extensions explains how to browse through and manipulate the object definitions in a directory service schema.
Standard objects and the remainder of the document defines each of the Active Directory standard object definitions.