An object of one embodiment of the present invention is to provide a display device and a driving method of a display device in each of which power consumption can be sufficiently reduced even in the case of displaying a moving image. In the display device and the driving method of a display device, a display screen is divided into a plurality of sub-screens in a row direction (a direction of a gate line) and image data in sequential frame periods is compared for each of the sub-screens. Whether or not the image data is rewritten is controlled on the basis of results of the comparison. In other words, writing is performed only in a region of the screen where rewriting is needed.