Extended Reality (XR) is an umbrella term that encompasses several immersive technologies: Virtual Reality (VR), Augmented Reality (AR), and Mixed Reality (MR). These technologies create immersive experiences by blending digital and physical worlds. 

Virtual Reality (VR) is a fully immersive experience where the user is completely surrounded by a computer-generated environment. VR typically requires a headset to block out the physical world and immerse the user in a virtual one. The VR world can be very realistic (e.g., skydiving) or cartoonlike (e.g., Horizon Worlds).

Augmented Reality (AR) is an interactive experience where digital elements are overlaid onto the real world. AR enhances the user's perception of reality by adding digital components, such as images, sounds, or other data. This is often experienced through devices such as smartphones, AR glasses, or headsets. 

Mixed Reality (MR) is a hybrid of VR and AR, where digital and physical objects coexist and interact in real-time. MR merges the physical and digital worlds, allowing users to interact with both simultaneously. One example of MR technology (as seen below) is Microsoft's HoloLens.

These technologies are collectively referred to as XR because they extend the reality we perceive by blending digital and physical elements in various ways.