Augmented reality (AR) generates a composite view that combines the real world environment with virtual objects. AR enhances perception by overlaying graphics, sounds, and other sensory enhancements onto real-world environments in real-time. Main hardware for AR includes displays, tracking systems, input devices and sensors. Current applications of AR include navigation assistance, medical training, repair/maintenance, education, games, shopping, and civil engineering. While promising benefits, AR also faces challenges including accuracy of location tracking indoors, cost, and potential negative impacts on perceptions of reality.