Microsoft's Hyper-V is a virtualization product that enables you to create and run multiple virtual machines (VM) on supported hardware. You can create multiple operating systems on one physical computer. All installed operating system can interact with one another while being isolated from one another. Virtualization is used to optimize and increase the efficiency in the use of your resources. This frees up hardware resources for other uses.
Hyper-V Server is a built-in feature of Microsoft Windows Server Datacenter Edition and must be enabled before you can use it. When enabled, Hyper-V Manager and associated PowerShell commands also become available.
Hyper-V Servers are managed using the built-in Hyper-V Manager or using the System Center Virtual Machine Manager (SCVMM) software installed on a different device. With the Hyper-V Manager, you can manage virtual machines on a single instance of Hyper-V Server on which the Hyper-V Manager is installed. SCVMM is used to manage a larger setup containing a large number of Hyper-V Servers.