Physics · Optics, Nature of Light and Optical Instruments

Holography is a technique that uses laser and photographic plates to produce three-dimensional images of objects on film by encoding not just the intensity but also the phase information of the light striking the film. 

Tomography is imaging by sections that use any kind of penetrating wave. It is often used in X-rays, biology, radiology, archaeology, etc 

Holography is a technique that uses laser and photographic plates to produce three-dimensional images of objects on film by encoding not just the intensity but also the phase information of the light striking the film. 

Electrography is recording the electrical activity of any part of the body.

Xerography is a dry photographing technique. It is an electrostatically charged-based technique for photocopying and printing documents. It is most commonly used in laser printers, photocopiers, and fax machines to reproduce and print images, data and office documents, etc.