In 1994 Paul Milgram and Fumio Kishino defined a mixed reality as “…anywhere between the extrema of the virtuality continuum.”
Mixed reality was also defined in Doug A. Bowman’s 2004 textbook 3D User Interfaces: Theory and Practice as “… a continuum including both VEs and AR. An environment’s position on the continuum indicates the level of “virtuality” in the environment…” Bowman was hired by Apple in early 2016.
While today MS has certainly co-opted it for marketing purposes, the term itself represents a broad and extremely interesting concept worth reading about. Words are just words, and it’s the least important aspect in the end, but I thought I’d share this with you anyway in case you didn’t know.