Virtual reality
The 1990s saw the first widespread commercial releases of consumer headsets. In 1991, Sega announced the Sega VR headset for arcade games and the Mega Drive console. It used LCD screens in the visor, stereo headphones, and inertial sensors that allowed the system to track and react to the movements of the user's head. In the same year, Virtuality launched and went on to become the first mass-produced, networked, multiplayer VR entertainment system. It was released in many countries, including a dedicated VR arcade at Embarcadero Center in San Francisco. Costing up to $73,000 per multi-pod Virtuality system, they featured headsets and exoskeleton gloves that gave one of the first "immersive" VR experiences. "Computer Gaming World" predicted "Affordable VR by 1994".
Virtual world
Among the earliest virtual worlds implemented by computers were virtual reality simulators, such as the work of Ivan Sutherland. Such devices are characterized by bulky headsets and other types of sensory input simulation. Contemporary virtual worlds, in particular the multi-user online environments, emerged mostly independently of this research, fueled instead by the gaming industry but drawing on similar inspiration. While classic sensory-imitating virtual reality relies on tricking the perceptual system into experiencing an immersive environment, virtual worlds typically rely on mentally and emotionally engaging content which gives rise to an immersive experience.