Guest OS (Operating System)

in a hosted environment, the operating system running in a virtual machine created on top of the host operating system and supported by the virtualization software. Compare to host operating system.

The operating system installed inside a virtual machine (or a partition). In a virtualization solution the guest OS can be completely different from the host OS. In a partitioning solution the guest OS must be identical to the host OS.

An operating system running in a virtual machine environment that would otherwise run directly on a separate physical system.

An operating system that runs inside a virtual machine. See also Host Operating System.