OpenLDAP is an open source implementation of LDAP or Lightweight Directory Access Protocol . OpenLDAP allows to store and organize user related data centrally. OpenLDAP functions like a relational database & can store any data but its normally used as a address book. Its used for authenticating and authorizing of the users. Information stored in OpenLDAP is in hierarchical manner & We can group the users into a single or multiple groups based on necessity.