Windows Server is an extremely versatile, multi-purpose operating system with dozens of roles and hundreds of features, including guest privileges. The myriad of Windows Server roles include Active Directory Certificate Services, Active Directory Federation Services, Active Directory Domain Services (AD DS), AD Rights Management Services, DHCP servers, and DNS servers. Hyper-V, print and document services, remote desktop services and Windows deployment services are also available as server roles. Direct Access as well as Volume Activation Services and Windows System Resource Manager are part of the comprehensive Windows Server Standard features.