Object classes are sets of related information objects that form entries in a Directory Information Tree (DIT). The Directory Server uses the schema to define these entries, to specify the position of the entries in a DIT, and to control the operation of the server. You can also extend the schema by adding your own schema definitions.

Object classes have the following general properties:
  • Object classes must have a globally unique name or identifier.
  • Object classes specify the required and allowed attributes in an entry.
  • Object classes can inherit the properties and the set of allowed attributes from its parent object classes, which may also be part of a hierarchical chain derived from the top abstract object class.
  • Object classes that are defined in the PingDirectory Server can be searched using the objectClasses operational attribute. The Directory Server also has a special entry called the subschema subentry, which provides information about the available schema elements on the server.