- AR is virtual object overlying a real world.
- VR is placing our avatar into a interactive virtual world.
- MR is interactive AR by gesture, thus VR+AR. It uses Hololens e.g. MS product. https://youtu.be/LzS1zI5Cvzc
- Metaverse is networked VR or VR with shared space.
- XR (Extended reality) is a super set of AR, VR, and MR that enables interactive digital twin.