Holography is the science and practice of making holograms, which are normally encodings of light fields rather than of images formed by a lens. Holograms are usually intended for displaying three-dimensional images. The holographic recording itself is not an image; it consists of an apparently random structure of varying intensity, density or surface profile. When it is suitably lit, the original light field is recreated and the view of the objects that used to be in it changes as the position and orientation of the viewer changes, as if the objects were still there.
The Hungarian-British physicist Dennis Gabor (in Hungarian: Gábor Dénes), was awarded the Nobel Prize in Physics in 1971 "for his invention and development of the holographic method".His work, done in the late 1940s, built on pioneering work in the field of X-ray microscopy by other scientists including Mieczysław Wolfke in 1920 and WL Bragg in 1939. The discovery was an unexpected result of research into improving electron microscopes at the British Thomson-Houston (BTH) Company in Rugby, England, and the company filed a patent in December 1947 (patent GB685286). The technique as originally invented is still used in electron microscopy, where it is known as electron holography, but optical holography did not really advance until the development of the laser in 1960. The word holography comes from the Greek words ὅλος (hólos; "whole") and γραφή (graphḗ; "writing" or "drawing").