Augmented Reality (AR) is an extension to Virtual Reality (VR). In VR things are pure artificial (hence virtual). Augmentation of reality is the ability to enhance the visible real things around you. When speaking about augmentation in the context of any electronical devices, in most cases it means an overlay of additional information onto an image or live view taken by a camera or a projection against a transparent surface (like glass). First use of AR was in military applications, e.g. in a jet fighters to increase reaction speed of pilots in critical situations or attack. The AR feature is nowadays often seen in cars for highlighting signs, barriers, obstacles, pedestrians and other things using a projection onto the windshield. This enhances safety thru better situation awareness.