When you scan a document, you see a light moving from one end of the document to the other end. As the light moves, it collects information about the document and converts it into an image format.

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The image format contains several lines – horizontal and vertical – creating a number of squares. Each square is called a dot or point. Your scanner studies the document from the left-most part and stores document information in pixel (point) format. This format contains the number of pixel in X,Y plane and color (in RGB format) of the portion of document. An example format can be 0,0, 12, 20, 49. Here, the first two numbers refer to the pixel position – X = 0 and Y = 0, meaning topmost dot. If the number of X increases, the information would be pertaining to the next line. Increase in Y is increase in horizontal position of the document. The remaining three numbers refer to the code of colors – Red, Green, and Blue. Most of the scanners and digital displays (including cameras and camcorders) use these color combination to produce millions of colors.
The image here shows a circle stored as an image, where the dots symbolize pixels or points that the scanner creates to store the document information.
Whatever document you store, be it text, image, or a combination of both, it is always converted to a graphic format where you need an image editing software to edit it.