Resolution refers to the amount of information that a scanned image contains. Resolution is measured in dots per inch (dpi). The dots are the pixels that create the digital image. A resolution of 72dpi signifies that in each inch of the image there exist 5184 pixels (72 x 72) in every square inch. Dpi is also known as pixels per inch (ppi) as well as ‘res’ (the metric resolution for each millimeter).