Virtual Reality (usually called VR) is a term that refers to a
computer generated environment where sight, sound, and
sometimes even touch are simulated to create pictures,
sounds and objects that actually seem real. A participant
enters this simulated environment through a head mounted
display (HMD) and interacts using a hand held control or a
glove. VR systems create full colour 3-D images, track the
participants body movements - usually head and hand
motions - and change the image instantly as the participant
interacts and moves through the virtual world.