Hyper-V is Microsoft’s flagship enterprise server virtualization platform. Hyper-V is a feature of Windows Server 2008 and it is required to be run on system with a 64-bit CPU. Its Hypervisor is about 100k, the Hyper-V role is about 100Mb, and Windows Server 2008, fully installed is multiple GB. The centralized management platform for Hyper-V is System Center Virtual Machine Manager.
Figure 1: Image Source: Wikipedia