This document discusses augmented reality (AR) and its applications. It begins with an abstract that defines AR as a technology that augments the real world with computer-generated sensory input. It then covers how AR works, the differences between AR and virtual reality, components of an AR system like head-mounted displays and tracking systems, and recent advances in AR technologies like Google Glass. Finally, it discusses several applications of AR in fields like medicine, archaeology, tourism, translation, navigation, industrial design, the military, and education.