VR - Virtual Reality

Hospital Corpsman 2nd Class Tim Sudduth, from Vashowish, Wash., demonstrates the Virtual Reality (VR) parachute trainer, while Aviation Survival Equipmentman 1st Class, Jackie Hilles, from Ekland, Penn., controls the program from a computer console

Virtual Reality is the computers used to stimulate a real or imagined environment that appears as a three dimensional (3-D) space. Example VR world is a room with furmiture and users walk through by moving an input device forward, backward or to the side.

For further explaination, examples, timeline etc, you can find it at Wikipedia Encyclopedia http://en.wikipedia.org/wiki/Virtual_reality