Holography is a technique that records and reconstructs the light scattered from an object to preserve its 3D information. It works by recording the time-varying light field of a scene during the recording phase and then regenerating it during the reconstruction phase. The main types of holograms are reflex, transmission, and computer-generated. Holography has many advantages like providing glasses-free 3D displays without the need for a projection screen and improving virtual and augmented reality, telepresence, and more.