The resolution of a screen refers to how many pixels are running across the length and height. For example, a resolution of 800×600 has 800 pixels along the width of the display, with 600 pixels going up the height. This makes for a screen total of 480 000 pixels.
The higher the resolution, the sharper the image on screen, as more detail can be shown. The most common desktop resolution is 1024×768, while the most common industrial resolution is 640 x 480. This is because a computer is typically displaying much more information, and the extra resolution is simply not needed in industrial applications.