Microsoft® Active Directory® directory service schema defines the attributes and classes used in Active Directory. The base schema that is included the system contains a rich set of class definitions, such as user, computer, and organizationalUnit, and attribute definitions, such as userPrincipalName, telephoneNumber, and objectSid. The existing set of classes and attributes will be sufficient for most applications. However, the schema is extensible, which means that you can define new classes and attributes. This section discusses extending the Active Directory schema.
Topics in this section include:
For more information and an overview of the Active Directory schema, including information about the schema implementation, class definitions, and attribute definitions, see Active Directory Schema.
For more information, including reference pages for the predefined schema classes, attributes, and attribute syntaxes, see the Active Directory Schema Reference in the Active Directory Reference.