1.4. Active Directory–Based Group Policy
To use Group Policy in a meaningful way, you need an Active Directory environment. An Active Directory environment needn't be anything particularly fancy; indeed, it could consist of a single Windows 2000, Windows 2003, or Windows Server 2008 Domain Controller and perhaps just one Windows XP or Windows Vista workstation joined to the domain.
But Active Directory can also grow extensively from that original solitary server. You can think of an Active Directory network as having four constituent and distinct levels that relate to Group Policy:
The local computer
The organizational unit (OU)
The rules of Active Directory state that every server and workstation must be a member of one (and ...