Scanning is process of dividing an image on the screen into a large number of very small squares formed by sets of horizontal and vertical straight lines.
Iconoscope is used for the purpose of scanning. It is a type of camera consisting of a cathode ray beam and a photoelectric cell. It is focussed onto an object to be televised. The image of the object formed by the lens of a camera is focussed onto a screen. On the screen, the image is divided into a very large number of every small squares formed by sets of horizontal and vertical straight lines. This process is called scanning