A hologram is a three-dimensional image, created with photographic projection. Unlike 3D or virtual reality on a two-dimensional computer display, a hologram is a truly three-dimensional and free-standing image that does not simulate spatial depth or require a special viewing device.
Holography dates back to 1947, when British/Hungarian scientist Dennis Gabor developed the theory of holography while he was working on improving the resolution of an electron microscope. Dennis Gabor coined the term hologram from the Greek words "holos" (meaning 'whole') and gramma (meaning 'message'). The development of laser technology in 1960 made holography a reality.