Directories are best suited to solving one set of problems and can be less satisfactorily applied when trying to solve problems it was not intended to solve. Databases are more appropriate for writing large volumes of data and can handle large and diverse transactions. On the other hand, a directory can be an appropriate choice for more than simple retrieval and storage information. The Complementary Directory Directories can create synergy among all the services in your enterprise. Directories can serve as a network-accessible storage device for information about configuration, access control, user preferences and profiles, etc.
Directories can help organize and access information contained in the web server itself.
As people began to use computers to collaborate and communicate with others, directories expanded to include basic contact information about the users of the systems. Grapevine, one of the most significant early distributed systems, was connected by Ethernet LAN and WAN links and included a Registration Database that served many of the same purposes as the directory systems of today. This Registration Database contained information about people, groups of people, and servers on the network. The Internet spawned many directory services development, including the development of LDAP itself. For example, DNS was designed as a widely distributed system with distributed administration and control.