Virtual reality

Virtual reality (VR) typically refers to computer technologies that use software to generate realistic images, sounds and other sensations that replicate a real environment (or create an imaginary setting), and simulate a user's physical presence in this environment. VR has been defined as "...a realistic and immersive simulation of a three-dimensional environment, created using interactive software and hardware, and experienced or controlled by movement of the body"^[1] or as an "immersive, interactive experience generated by a computer".^[2]
A person using virtual reality equipment is typically able to "look around" the artificial world, move about in it and interact with features or items that are depicted on a screen or in goggles. Most 2016-era virtual realities are displayed either on a computer monitor, a projector screen, or with a virtual reality headset (also called head-mounted display or HMD). HMDs typically take the form of head-mounted goggles with a screen in front of the eyes. Programs may include audio and sounds through speakers or headphones.
Advanced haptic systems in the 2010s may include tactile information, generally known as force feedback in medical, video gaming and military training applications. Some VR systems used in video games can transmit vibrations and other sensations to the user via the game controller. Virtual reality also refers to remote communication environments which provide a virtual presence of users with through telepresence and telexistence or the use of a virtual artifact (VA). The immersive environment can be similar to the real world in order to create a lifelike experience or it can differ significantly from reality where gamers can use fictional powers.

Etymology and terminology

Paramount for the sensation of immersion into virtual reality are a high frame rate (at least 95 fps), as well as a low latency. Furthermore, a pixel persistence lower than 3 ms is required, because if not, users will feel sick when moving their head around.

In 1938, Antonin Artaud described the illusory nature of characters and objects in the theatre as "la réalité virtuelle" in a collection of essays, Le Théâtre et son double. The English translation of this book, published in 1958 as The Theater and its Double,^[3] is the earliest published use of the term "virtual reality". The term "artificial reality", coined by Myron Krueger, has been in use since the 1970s. The term "virtual reality" was used in The Judas Mandala, a 1982 science fiction novel by Damien Broderick. "Virtual" has had the meaning "being something in essence or effect, though not actually or in fact" since the mid-1400s, "...probably via sense of "capable of producing a certain effect" (early 1400s)".^[4] The term "virtual" has been used in the computer sense of "not physically existing but made to appear by software" since 1959.^[4]
Virtual reality is also called "virtual realities", "immersive multimedia", "artificial reality"^[5] or "computer-simulated reality". A dictionary definition for "cyberspace" states that this word is a synonym for "virtual reality", but the two terms are fundamentally different (something that is "virtual" does not necessarily need to rely on a network, for instance).^[6]
Virtual reality shares some elements with "augmented reality" (or AR). AR is a type of virtual reality technology that blends what the user sees in their real surroundings with digital content generated by computer software. The additional software-generated images with the virtual scene typically enhance way the real surroundings look in some way. Some AR systems use a camera to capture the user's surroundings or some type of display screen which the user looks at (e.g., Microsoft's HoloLens, Magic Leap).