Virtualization describes the separation of a resource or request for a service from the underlying physical delivery of that service. For example, with virtual memory, computer software gains access to more memory than is physically installed by background swapping of data to disk storage.
Similarly, virtualization can be applied to other IT infrastructure layers - including networks, storage, laptop or server hardware, operating systems and applications. This blend of virtualization technologies - or virtual infrastructure - provides a layer of abstraction between computing, storage and networking hardware, and the applications running on it
