Information can be requested from each entry that matches the criteria. For example, you might want to search the entire directory subtree below the University of Michigan for people with the name Barbara Jensen, retrieving the email address of each entry found. LDAP lets you do this easily. LDAP lets you do this too. The next section describes in more detail what you can do with LDAP and how it might be useful to you.
Some directory services provide no protection, allowing anyone to see the information.
LDAP provides a method for a client to authenticate, or prove its identity to a directory server, paving the way for rich access control to protect the information the server contains. LDAP directory service is based on a client-server model. One or more LDAP servers contain the data making up the LDAP directory tree. An LDAP client connects to an LDAP server and asks it a question. Slapd is an LDAP directory server that runs on many different UNIX platforms.