The absolute size of a pixel depends on the screen resolution. The resolution is a number like 1024 x 768, corresponding to the number of pixels in your display. Since your monitor always stays the same size, the number of pixels in your display determine how big each pixel is. Imagine a resolution of 2 x 2, or four pixels per monitor. In general, the lower the resolution, the larger each pixel is.
Large pixels can make things easier to see, but they sometimes make images look blocky or jagged.
For example, at low resolutions, a diagonal line may look like a string of squares rather than one continuous line. You need to choose a resolution that makes the images on your screen the clearest for you. Changing the monitor resolution Note that on the Macintosh keyboard, the Command key is the one with the picture of the apple on it. You can do this with the mouse , which is the easiest option, but it is also possible to do this using only the keyboard . The Monitor button is the default.