LDAP (Lightweight Directory Access Protocol) is a mature and flexible mechanism for interacting with directory servers. The mechanism authenticates and stores information about users, groups, and applications. The common LDAP use is to provide a central place for authentication which means it stores user names and passwords.
An LDAP directory server is a general-purpose datastore used in various applications or services to validate users with a plug-in. For example, an LDAP can validate user names and passwords with the Docker, Jenkins, Kubernetes, Open VPN, and Linux Samba servers. System administrators can also use the LDAP single sign-on to control access to an LDAP database.