Active Directory Schema Technical Reference
Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2, Windows Server 2008, Windows Server 2008 R2, Windows Server 2012, Windows Server 2012 R2
The schema is the component of the Active Directory directory service that defines all the objects and attributes that the directory service uses to store data. You can combine some objects in the schema to create more-complex definitions if objects of greater complexity are required. You can also add new definitions to the schema to support new types of objects in the directory.
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