Box 1.

Categories of extended reality technologies3–5

Extended reality (XR) is an overarching term that encapsulates current and future developments in augmented reality, mixed reality and virtual reality.
Augmented reality (AR): The superimposition of digital data onto the real world
Mixed reality (MR): A seamless integration of both virtual and digital environments that may be interacted with
Virtual reality (VR): A technology that possesses three main characteristics:
  • Primarily first (sometimes third) person perspectives within the scenario

  • Real-time interaction with a virtual environment

  • The user is completely surrounded by the virtual environment