Wikipedia
A hypervisor (or virtual machine monitor, VMM, virtualizer) is a kind of emulator it is computer software, firmware or hardware that creates and runs virtual machines A computer on which a hypervisor runs one or more virtual machines is called a host machine, and each virtual machine is called a guest machine The hypervisor presents the guest operating systems with a virtual operating platform and manages the execution of the guest operating systems Multiple instances of a variety of operating systems may share the virtualized hardware resources: for example, Linux, Windows, and macOS instances can all run on a single physical x86 machine
Hypervisor - Wikipedia, the free encyclopedia