Solution:
Hypervisor
Explanation:
Server virtualization in Windows Server 2012 R2 is based on a module called a hypervisor. Sometimes called a virtual machine monitor (VMM), the hypervisor is responsible for abstracting the computer's physical hardware and creating multiple virtualized hardware environments, called virtual machines (VMs)
Another Explanation:
The Windows Server 2012 operating system remains above the hypervisor layer, despite the fact the Hyper-V role is installed from within the Windows Server operating system. The physical server where Hypervisor or Hyper-V server role is installed is called the host machine or virtualization server. Hyper-V 2012 R2 is Microsoft's virtualization platform, or 'hypervisor', which enables administrators to make better use of their hardware by virtualizing multiple operating systems to run off the same physical server simultaneously. Configuration Manager 2012 supports Windows 10 version 1507 (build 10.0. 10240) and 1511 (build 10.0. 10586) for the lifecycle of these builds.