In a computing environment, virtualization means to create a virtual version of a resource or device (i.e. server, storage device or an operating system).   This provides a framework that divides the resource into one or more execution environments.

A simple example of virtualization is the partitioning a hard drive because you take one drive and partition it to create two separate hard drives. Applications, devices and computer users are then able to interact with the virtual resource as if it were a real single logical device.

The term virtualization has become somewhat of a buzzword and as a result the term is often used in the following contexts:

• Storage Virtualization: the combining of multiple network storage devices into what appears to be a single storage unit.
   
• Server Virtualization: the partitioning a physical server into smaller virtual servers.

• Operating System-level Virtualization: a type of server virtualization technology which works at the operating system (kernel) layer.

• Network Virtualization: using network resources through a logical segmentation of a single physical network.