Augmented reality (AR) combines the real world with virtual elements. AR works by tracking a user's position, computing virtual objects, and displaying them overlaid on the real world through a head-mounted display. The key components of AR are head-mounted displays, tracking systems, and mobile computing power. AR has applications in medicine for surgical planning, education for enhancing lessons, the military for enhancing situational awareness, games for blending virtual and real worlds, and maintenance/construction for overlaying instructions. While tracking and size limitations currently exist, AR has huge potential to blur real and virtual experiences.