This document discusses augmented reality (AR), which combines real and virtual elements to enhance one's current perception of reality. It describes how AR systems work by superimposing graphics, sounds, and other information over a real-time view using devices like head-mounted displays. The key components required for AR are displays, tracking systems to detect the user's location and orientation, and mobile computing power. The document outlines several potential applications of AR technology in fields like education, military, tourism and gaming.