Virtual Reality (VR) means the simulation of a person’s entire environment (sights, sounds, movements, etc.) by computer. Most commonly this is done by displaying a realistic picture like Three-Dimensional Graphics and allowing the user to manipulate objects by clicking on them with the mouse or keyboard.
Truly realistic virtual reality is more a goal than an existing technology, but some computer games achieve a limited kind of realism by having the user wear a special helmet and gloves and/or stand on a special platform.
Recent tech devices like Oculus Rift, HTC Vive implements virtual reality as an example.