Mixed reality (MR) (encompassing both augmented reality and augmented virtuality) refers to the merging of real and virtual worlds to produce new environments and visualizations where physical and digital objects co-exist and interact in real time. The term encompasses both augmented reality, where digital information and virtual objects augment images of the real world, and augmented virtuality, where real objects augment artificial computer-generated images co-exist.

According to Paul Milgram and Fumio Kishino the Virtuality Continuum extends from the completely real through to the completely virtual environment with augmented reality and augmented virtuality ranging between. In this context mixed reality  is defined as "..anywhere between the extrems of the virtuality continuum”.