The resolution of an image describes how fine the dots are that make up that image. The more dots, the higher the resolution. A 300 dpi (dots per inch) printer is capable of printing 300 dots in a line 1 inch long. This means it can print 90,000 dots per square inch. When displayed on a monitor, the dots are called pixels. A 640-by-480-pixel screen is capable of displaying 640 distinct dots on each of its 480 lines, or about 300,000 pixels.