A technique that has grown out of virtual reality, where rather than synthesising a non-existent world, you take reality and combine it with some virtual aspect. For example, say you're a repairman. You look at a car's engine and all you see are parts. Not very exciting. But you put on your augmented reality headset and all of a sudden, superimposed on the engine is a schematic diagram showing what's connected to what; which makes your job easier.

Unfortunately, because of the way the world works, the most probable early consumer of this technology will be the military. So you'll put on your AR headset, you'll look around and enemies will be labelled with distance etc, or outlined in red if you're supposed to shoot them; while your friends are outlined in green.