LDAP stands for Lightweight Directory Access Protocol. LDAP uses TCP or UDP Port 389.
LDAP is used to query directories.
If you’ve logged in to a corporate network for the first time, VPN, or a web server on the corporate network, you’re probably used to entering your username and password. This authentication is provided to a centralized database. LDAP is a common form of this centralized database.
With LDAP you can store and retrieve information in a single network directory database, such as Microsoft Active Directory. Windows uses LDAP commands to update Active Directory to enable, disable, or change accounts.