A hypervisor allows multiple operating systems to run concurrently on a host computer — a feature called hardware virtualization.

The hypervisor presents the guest operating systems with a virtual platform and monitors the execution of the guest operating systems. In that way, multiple operating systems, including multiple instances of the same operating system, can share hardware resources.

Unlike multitasking, which also allows applications to share hardware resources, the virtual machine approach using a hypervisor isolates failures in one operating system from other operating systems sharing the hardware.