About the Directory Schema

The directory schema is the description within a Microsoft Exchange Server directory of all object classes and objects, and their attributes and inheritance structure. For programming purposes, every person, workgroup, location, gateway, mailbox agent, and resource within a Microsoft Exchange Server organization can be considered an object in the directory with a set of attributes. Groups of objects with the same attributes belong to the same object class. In other words, an object’s class defines the set of attributes it possesses. A single, specific object in the class is referred to as an instance of the object class. For example, JohnJ (the e-mail name for John Jones) is an instance of the Mail-Recipient class.