Definition: A hologram is a three-dimensional image formed by the interference of light beams from a laser or other coherent light source. It is a photographic recording of a light field, used to display a fully three-dimensional image of the holographed subject, which can be seen without the aid of special glasses or other intermediate optics.
Etymology and Origin: The term ‘hologram’ is derived from the Greek words ‘holos’, meaning ‘whole’, and ‘gramma’, meaning ‘message’ or ‘writing’. The word was coined in 1949 by Hungarian-British physicist Dennis Gabor, who developed the principles of holography. He used ‘holos’ to indicate the completeness of the image information captured, and ‘gramma’ to refer to the recording process.