Augmented reality (AR) overlays digital content onto the real world. Examples include Pokémon Go, where virtual creatures appear in real-world locations, and IKEA apps that let users visualize furniture in their homes. AR uses sensors like GPS, gyroscopes, and accelerometers to understand the user’s location and orientation. Some AR applications use markers (like QR codes) to trigger digital content, while others are markerless, relying on pattern recognition.