Overview#LDAP Model of User Information (RFC 4512) As X.501 states:
The purpose of the Directory is to hold, and provide access to, information about objects of interest (objects) in some 'world'. An object can be anything which is identifiable (can be named).
An objectClass is an identified family of objects, or conceivable objects, which share certain characteristics. Every object belongs to at least one class. An object class|objectClass] may be a subclass of other object classes, in which case the members of the former class, the subclass, are also considered to be members of the latter classes, the superclasses. There may be subclasses of subclasses, etc., to an arbitrary depth.
An object entry represents a particular object. An alias entry provides alternative naming. A subentry holds administrative and/or operational information.