This document provides an overview of augmented reality (AR), including its definition, evolution, components, implementation methods, applications, and future possibilities. AR enhances the real-world environment by overlaying digital content and information. The key components of an AR system are displays, tracking systems, and mobile computing power. Implementation can be done via markers, markerless recognition, or location-based methods. Applications include medical, education, military, tourism and more. The future of AR may include replacing cell phones and expanding computer screens into the real world.