a software implementation of a computer system, allowing one physical computer to run several &"virtual computers&", each with their own independent operating system and application software.
a software implementation of a computer that executes programs like a physical computer. appears to the user as a separate independent computer with its own operating system.
a self-contained operating environment, imposed through software, that takes on the function of / behaves like a separate computer, often used to run intermediate code or an operating system