Active Directory (AD) is an implementation of LDAP-likeirectory services by Microsoft for use primarily in Windows environments. Its main purpose is to provide central authentication and authorization services for Windows-based computers. Active Directory also allows administrators to assign policies, deploy software, and apply critical updates to an organization. Active Directory stores information and settings in a central database. Active Directory networks can vary from a small installation with a few hundred objects, to a large installation with millions of objects (though not easily ).