Lightweight Directory Access Protocol (LDAP)
The Lightweight Directory Access Protocol (LDAP) is a protocol that provides a mechanism to access and query directory services systems. These directory services systems are most likely to be Novell Directory Services (NDS) and Microsoft's Active Directory. Although LDAP supports command-line queries that are executed directly against the directory database, most LDAP interactions will be via utilities such as an authentication program (network logon) or locating a resource in the directory through a search utility. LDAP operates at the application layer of the OSI model.