Virtual realities are simulated worlds created by computers loaded with interactive software.
 Rather than keyboards, people can communicate with voice commands, finger pointing, head
 nodding, and other natural gestures. Rather than a video display terminal the machine's output
 comes on wrap-around screens, VDTs set into goggles (video goggles), DataGloves (computerized
 gloves with sensors), audio synthesizers, and other media able to create three-dimensional 
 sensations. The goal of the virtual reality field is to attain "presence" or the feeling of being here
 now. The ultimate goal is to simulate a landscape in which one can walk around and manipulate 
 objects at will -- a landscape so convincing that the word "virtual" disappears.