This document provides an overview of augmented reality (AR), including its definition, history, enabling technologies, current applications, and future outlook. AR enhances one's perception of reality by overlaying computer-generated sensory input like sounds, graphics and videos onto the real world in real time. The timeline shows early concepts from 1901 and the first interactive AR system in 1975, with recent growth driven by smartphones, tablets and advances in hardware/software. Current applications span industries like education, gaming, navigation, commerce and more, while future development focuses on improving AR devices and expanding its uses.