Virtual Desktop OS
Virtual desktops, using relatively low-resolution images to use as high-definition screen, for example, a screen is only 640X480 resolution of the system using the virtual desktop as a way to set the desktop 1280X960, the user can see only 640X480 while the screen, but can move the mouse or keyboard through the way to move the desktop, or mobile user's field of vision to other parts of the 1280X960.

Virtual Machine OS
Virtual machine, an operating environment, such as on a computer inside the stand-alone computers, can run other operating systems, or even for different processors (PROCESSOR) designed applications.

Virtual Memory OS
Virtual memory, an operating system (OS) management of memory (MEMORY) method, the operating system uses a look-up table of the way applications use memory addresses into actual memory addresses, and can temporarily certain now unused memory areas to move to temporary storage on your hard disk, so that the amount of memory available than the actual amount of memory to much more. the action is moving memory pages (PAGE) for the number of completed, it is called PAGING, some jobs system, known as SWAPPING, when the system memory to use is not a real memory area, while the need to page back from the hard disk, then known as PAGE FAULT, if the system often in PAGE FAULT, you will not find hard drive stop reading and writing.

Virtual Reality Multimedia
Virtual Reality, presented by the computer out of a virtual reality environment, image, users can use the display with the helmet and gloves and other equipment to a computer generated signal processing, to enable the computer to respond to the user's actions to change the computer generated image.