"In computing, virtualization or virtualisation (sometimes abbreviated v12n, a numeronym) is the act of creating a virtual (rather than actual) version of something at the same abstraction level, including virtual computer hardware platforms, storage devices, and computer network resources."
The management of virtualization within an operating system. This includes virtual machines, hypervisors, and containers.
"Virtualization began in the 1960s, as a method of logically dividing the system resources provided by mainframe computers between different applications."
"An early and successful example is IBM CP/CMS."
"The control program CP provided each user with a simulated stand-alone System/360 computer."
"Since then, the meaning of the term has broadened."