Virtual reality replaces the real world with a simulated one. It is a computer-simulated environment that can simulate physical presence in places in the real world or imagined worlds. Most current virtual reality environments are primarily visual experiences, displayed either on a computer screen or through special stereoscopic displays, and may include tactile information, generally known as force feedback in medical, gaming and military applications. Virtual reality is often used to describe a wide variety of applications commonly associated with immersive, highly visual, 3D environments. The development of CAD software, graphics hardware acceleration, head-mounted displays, datagloves, and miniaturization have helped popularize the notion.
The simulated environment can be similar to the real world in order to create a lifelike experience. For example, in simulations for pilot or combat training—or it can differ significantly from reality, such as in VR games.