Each pixel is turned on or off to make up the image. The entire image on a computer screen is made up of pixels. The resolution of the monitor is determined by the number of pixels on the screen. The higher the resolution, the more pixels, and the more space you have on your desktop for letters, numbers, windows, and images. The lower the resolution, the lower the number of pixels, and the less space you have available on your computer's desktop.
Resolution is measured in two ways.
Typical dot pitches for high performance monitors range from 0.22 mm to 0.26 mm. This dot pitch is the theoretical maximum resolution of the monitor, expressed as the distance between the holes in the shadow mask or aperture grill. Effective dot pitch is also a function of the sharpness of the electron guns and the quality and spacing of the phosphors. The second way to express the resolution is the number of horizontal pixels and the number of vertical pixels. The first is the number of pixels across the screen, and the second the number of pixels up and down.