Virtual Reality (VR) is the result of the combination of different existing technologies, which focus on the ability of man to interact with the machine in a new and revolutionary way. It is the result of the evolution of computer graphics, of visual simulation, of telepresence technologies. The pioneer in this field was Ivan Sutherland who introduced the concept of "Ultimate display" in 1965. He described it with these words: "A display connected to a digital computer gives us a chance to gain familiarity with concepts not realizable in the physical world... The screen is a window through which one sees a virtual world. The challenge is to make that world look real, act real, sound real, feel real"¹.