AR vs. MR, vs. VR

AR is augmented reality. If virtual reality is total immersion, augmented reality is all about layering virtual elements onto the real world. Pokémon Go is probably the most well-known example of this technique, with a nexus of magical animals layered onto a real-world map and what you can see with your phone’s camera.
Until recently, AR has been distinguished by a level of disconnect between the virtual and real world. You may have information imposed on your field of vision – like images or text, but these virtual elements are not anchored to the real world, and do not respond to physical objects in real-time.
Devices such as Google Glass were early attempts to integrate AR into headwear, but while there are reports that Apple is working on hardware dedicated to AR, and there are some crazy patents about AR contact lenses, the current mode for AR is to layer virtual elements using pre-existing devices such as smartphones and tablets.
MR is mixed reality. Mixed reality involves a strong element of interaction between physical and digital elements. The clearest case of this is Microsoft’s HoloLens, which can impose virtual models of buildings, bodies, and vehicles that designers can walk around, inspect and tweak as they see fit. Experimental hardware such as the Magic Leap and Intel’s Project Alloy prototype have given a glimpse of where this path could lead, potentially encompassing elements like haptics (touch).
The lines between AR and MR have blurred somewhat. You could argue the IKEA app, for example is a form of mixed reality as it allows users to walk around virtual furniture on a real-world carpet, as it if were a physical object. Some say MR is another way of saying ‘“true AR”. It is likely that, as digital-physical interactions become more sophisticated, one term will likely take over the other. Many believe mixed reality will prevail.
VR is virtual reality. It is most often used as an umbrella term for many immersive, computer-simulated environments. This means that you can probably get away with calling AR and MR subsections of VR.
Virtual reality is a totally computer-simulated version of reality (for sound and vision). Head-mounted displays like the Oculus Rift, HTC Vive, and PlayStation VR, as well as mobile-based headsets like Google Daydream and Samsung Gear, are all VR hardware. You strap them onto your face, and are immersed in a digital environment. Another subsection of VR is 360-degree video. Special cameras capture these images, so they are not computer-made virtual environments, but you still experience them using a VR headset.
Ideally, a VR user should feel like they have been transported from their living room into a totally different space. Having your field of vision taken up by a virtual world can trick your brain into feeling physically present within that reality. These ideas about presence and immersion and the potential for VR to communicate another person’s perspective, making a user feel physically involved in a way screen-based film cannot.

None of these should be confused with AI, artificial intelligence, which is a totally different topic.

Augmented Reality vs. Virtual Reality

Augmented reality (AR) is the result of using technology to superimpose information, such as sounds, images, and text on the world we see. It adds to what we see. An example is Google glasses. It displays videos and sounds onto the screen. The heads-up displays in many fighter aircraft shows information about the attitude, direction, and speed of the plane, and can show which objects in the field of view are targets. Some cars have begun showing a digital display on the windshield so drivers do not need to look down at the dash.
Phones and tablets offer AR, such as the Star Walk app, which allows a user to point the camera at the sky and see the names of stars and planets superimposed on the image. Another app called Layar uses the smartphone's GPS and its camera to collect information about the user's surroundings and displays information about nearby restaurants, stores, and points of interest. Another example is an app that allows translation of signs into a user's own language.

Virtual reality (VR) means computer-generated environments for you to interact with, and be immersed in. It replaces what we see by using a head set to block out the real world. As you move your head, the picture or video moves in the same direction, allowing a person to view a 360 degree virtual scene.

Researchers are developing holograms, which can take VR and AR a step further, since holograms can be seen and heard without a headset.