An LDAP (Lightweight Directory Access Protocol) server is used for managing and storing information about users, groups, and other directory objects within a network. This information can be used for authentication and authorization purposes, allowing users to access network resources and services based on their specific permissions and roles. LDAP servers are commonly used in enterprise environments for centrally managing user accounts, passwords, and access rights across multiple systems and applications. They can also be used for other purposes such as email address books, public directories, and phonebooks.