Microsoft HoloLens is an augmented reality headset that allows users to see holograms overlaid in their physical environment. It runs Windows 10 and does not require wires or connection to another device. HoloLens uses sensors to track user movement and gaze to interact with holograms using gestures and voice commands. Holograms are projected using two nanoprojectors and a transparent visor. Some potential applications include providing visual work instructions and medical guidance in complex environments.