Explanation

• Holography is a unique photographic image without the use of a lens.
• It is a recording of an interference pattern that uses diffraction to reproduce a 3D light field.
• This recorded interference pattern actually contains much more information than a focused image and enables the viewer to view a true 3D image that exhibits parallax.
  
• That is, the image will change its appearance if you look at it from a different angle,
•  just as if you were looking at a real 3D object.