Final answer:
Apple Mac OS X/macOS server employs Kerberos, Open Directory, and other directory services for authentication and managing user information.
Step-by-step explanation:
Apple Mac OS X/macOS server employs several authentication and directory services. One of the authentication services it uses is Kerberos, which provides secure authentication for users and services. Another authentication service is Open Directory, which is a directory service based on the Lightweight Directory Access Protocol (LDAP). Directory services in Mac OS X/macOS server include Open Directory, Active Directory, and Apple's own Directory Services.