Virtualization is the creation of a virtual (rather than actual) version of something, such as an operating system, a server, a storage device or network resources. Operating system virtualization is the use of software to allow a piece of hardware to run multiple operating system images at the same time. The technology got its start on mainframes,a decades ago, allowing administrators to avoid wasting expensive processing power.

Virtualization lets companies get more value out of their information technology investments by letting them divide their physical infrastructure in ways that let people, applications and other devices use them seamlessly as though they were a single resource