M.U.D (multi-user-domain) / M.O.O (multi-object-oriantated). textually described virtual worlds, where the user perceives the virtual environment through mental images, guided by an interactive surrounding.

A 3D virtual environment graphically displayed on a desktop computer monitor.

A 3D environment projected onto a screen. This allows the user to demonstrate concepts to a group of people, where several screens are used to surround the user with images, This is the most advanced form of projected VR in use today.

Most advanced flight, Ship and vehicle simulators are semi-imersive. The cockpit, bridge,or driving seat is a physical model, whereas the view of the perceived world outside is computer generated.

This is the most realistic form of VR, it consists of a 3D environment seen through a head mounted display, where the user feels part of the environment. Detached from reality, the user has no visual contact with the physical world.

The current uses of VR rely entirely on the equipment that has been developed, tested and produced, the equipment turns the ideas into reality.