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 gestures to interact with holograms. At the core is a computer with a CPU, GPU and HPU that processes data from 18 sensors. It projects holograms using two nanoprojectors and transparent lenses, allowing the user to see virtual objects blended with the real world. Some potential applications include providing visual work instructions and medical guidance in hazardous environments.