LDAP
LDAP (Lightweight Directory Access Protocol) is a protocol that is used to work with data on a directory server. Using LDAP, data can be stored in a tree structure, and then accessed. The most common use case is working with user information.
LDAP communicates over TCP/IP and is suitable for user authentication. It is mainly used to store data that does not change very often. In addition to login authentication, it is also useful for maintaining an inventory of a company’s assets or a contacts list.