Augmented Reality and Virtual Reality Are Not Two Technologies: Why VR, AR, MR, and XR Describe One Activity

This paper argues that virtual reality, augmented reality, mixed reality, and extended reality are four industry names for one underlying activity, spatial computing, rather than four separate technologies competing against each other. The paper credits Paul Milgram and Fumio Kishino's 1994 paper, A Taxonomy of Mixed Reality Visual Displays, published in IEICE Transactions on Information and Systems, which proposed a reality-virtuality continuum running from a fully real environment to a fully virtual one, as the first serious attempt to relate these labels to each other. That continuum still became part of the problem it tried to solve. A continuum describes multiple positions along its length, and multiple positions are exactly what an industry needs to justify multiple products. Two head-worn devices tracking six degrees of freedom can run the identical underlying activity while one is sold as virtual reality for gaming and the other as mixed reality for office work, with only the marketing separating them. The paper traces why the split persists commercially: separate categories claim separate shelf space, separate marketing budgets, and separate analyst reports, and two smaller growth figures make better headlines than one larger, steadier number describing a single market. It closes by returning to the distinction argued in the first paper of this series, screen computing against spatial computing, as the one distinction that still matters once the four labels are set aside. This is the second paper in the same five-part series.