directory information base (X.500) (DIB)
A Directory Information Base (DIB) is a database that stores Directory Services information in X.500 systems.
A DIB database contains all information and can store it in separate areas. The individual entries of the objects have a hierarchical relationship to each other.
The Directory SystemAgents( DSA) have direct access to the Directory Information Base (DIB) at the request of the Directory User Agents ( DUA).