The look and feel of your programs and especially the internet are determined by your computers display capabilities and settings.
Computer displays consist of a display adapter and monitor.
Lets start with the display adapter. The speed of these processors and the way they are connected to the computer determine how fast video is displayed on your monitor. The amount of memory installed on the display adapter also effects performance, but is mainly related to the quantity of colors that can be displayed at one time. The monitor is basically a very high resolution television. It converts the electrical signals from the display adapter into light focused as a picture on your screen.