Is used to look up information in a database for other users and network resources. The directory database itself can consist of a wide variety of information, including not only basic user contact information, such as email addresses or phone numbers, but also objects, such as printers and computers. Some directory services are used to configure and control access to every single network resource object on the entire network or to contain a centralized database of logins and passwords.
LDAP (Lightweight Directory Access Protocol)
With such a critical collection of network data, security is of prime importance when using directory access protocols such as LDAP. All LDAP servers have some security controls in place for allowing read and update access to the directory database. Typically, all users can read most of the information held in the database, but only a few users have update privileges. Large directories usually have multiple information administrators who have access to update only information pertaining to their departments or regions.