Why use higher resolutions?

Computer display units, whether they are LCD monitors, projectors or plasma screens are pixel based displays. The resolution you use or your display supports is the number of pixel columns by pixel lines i.e. 1024*768 (XGA) is 1024 columns of pixels by 768 lines. It follows from this that the higher the resolution the smaller the pixels for a given screen size. The smaller and more numerous the pixels, the finer the detail which can be displayed.