Extended Reality (XR) refers to all real and virtual environments generated by computer and wearables. The X in XR encompasses all other letters AR, MR, VR. The content that is interacted with ranges from real-world content such as sound, images, videos or 360° videos to computer generated 2D or 3D models, characters, animations, worlds and from mono or spatial sound to haptic feedback and smell, blended together as required.