1. Monitor
A Monitor (or "screen") is the most common form of output from a computer. It displays information in a similar way to that shown on a television screen.
On a typical computer the monitor may measure 17 inches (43 cm) across its display area. Larger monitors make working at a computer easier on the eyes. Of course the larger the screen, the higher its cost! Typical larger sizes are 19 inch, 20 inch and 21 inches.