Editing Execution (computing) (section)

== Virtual machine ==
{{main|Virtual machine}}
A ''virtual machine'' (''VM'') is the [[virtualization]]/[[emulator|emulation]] of a [[computer system]].  Virtual machines are based on [[computer architecture]]s and provide functionality of a physical computer. Their implementations may involve specialized hardware, software, or a combination.

Virtual machines differ and are organized by their function, shown here:

* '''[[System virtual machine]]s''' (also termed [[full virtualization]] VMs) provide a substitute for a real machine. They provide functionality needed to execute entire [[operating system]]s. A [[hypervisor]] uses [[native code|native execution]] to share and manage hardware, allowing for multiple environments which are isolated from one another, yet exist on the same physical machine. Modern hypervisors use [[hardware-assisted virtualization]], virtualization-specific hardware, primarily from the host CPUs.
* '''Process virtual machines''' are designed to execute computer programs in a platform-independent environment.

Some virtual machine emulators, such as [[QEMU]] and [[video game console emulator]]s, are designed to also emulate (or "virtually imitate") different system architectures thus allowing execution of software applications and operating systems written for another [[CPU]] or architecture. [[OS-level virtualization]] allows the resources of a computer to be partitioned via the [[Kernel (operating system)|kernel]]. The terms are not universally interchangeable.