A Microsoft technology that constitutes an LDAP directory service with centralized management functionality for user accounts, computer accounts, groups, and configuration management across many Windows servers and desktops.
Active Directory is a directory service created by Microsoft for managing Windows environments.
It is used for:
- A centralized Authentication/Authorization source for Kerberos and NTLM protocols.
- Providing a single authentication/authorization domain for member servers and workstations.
- Providing LDAP services.
- Providing centralized configuration methods of Windows workstations and servers through Group Policy and other methods.
- Multi-site replication of directory-database data.
Non-Windows support is generally provided through the Samba package on POSIX operating systems (Linux, macOS, BSD, Solaris, etc). All modern Samba releases allow machines to join a domain as if they were a Windows machine.
For a list of ports which must be open in a firewall for AD to work properly, see http://serverfault.com/questions/304484/what-firewall-ports-need-to-be-open-for-active-directory.
Some useful links are below
