Virtual Technology refers to the use of specific computer technologies that use a virtual reality headset to simulate realistic images and videos as well as display a virtual world to the user. The user's physical presence in the virtual world is also recognized and what the user does in the real world happens in the virtual world. The technology used in these headsets have been used in a variety of different mechanisms.
Virtual reality was first experimented was in 1838 by Charles Wheatstone and his stereoscope. His research that demonstrated that when the user looks through the stereoscope their brain processes the two images from each eye into a single object of three dimensions. Viewing two side by side stereoscopic images or photos through a stereoscope gave the user a sense of depth and immersion.
Later on in the 90s, virtual reality was implemented through the use of vector graphics and a stereoscopic 3d display in arcade machines. These would be a primitive style of virtual reality that focused on polygons that made the illusion of 3-dimensional graphics.
Soon after vector graphics were being experimented with, the concept of a virtual reality headset would soon be undertook starting with "The Sword of Damocles" made by Ivan Sutherland and his student Bob Sproull. Future iterations of the Vr headset would continue to be modified in order for it to be more comfortable and useful for the user such as with updated graphics and a more advanced environment.