Glossary

This describes technology that emulates hardware to enable multiple operating systems to co-exist on the same platform. Typically a hypervisor is used to deliver the hardware emulation. With hardware virtualization a complete OS is run in each virtual session including kernel, directory structures and user mode OS services.

A hypervisor exists as a control layer between the hardware operating system(s). A hypervisor allows multiple operating systems to run on the same physical hardware. There are two common types of hypervisor architectures; bare-metal or hosted. Bare-metal architecture enables the hypervisor to run directly on the hardware (with no other OS needed).
In a hosted architecture (type 2) the hypervisor resides on top of an existing installed OS, which in turn hosts guest OSs above it (total of three layers).