Nearly everyone has heard of virtual reality (VR) and augmented reality (AR), and while these terms tend to be used in different ways, all involve creating a digital world. In VR, the user enters a wholly digital world, as in Second Life or World of Warcraft; in AR digital content is projected onto the real world, as with the creatures in Pokémon Go that are projected onto the user’s surroundings, or images of pre-earthquake San Francisco superimposed on current views of the city.
