An electronic visual display used for computers is called a monitor. It has a display device, an enclosure as well as a circuitry. In modern monitors, this display device is a thin panel of TFT-LCD (Thin Film Transistor Liquid Crystal Display). On the other hand, earlier the monitors consisted of CRT (Cathode Ray Tube) which was as deep as the size of the screen.
Earlier, the computer monitors were used for the purpose of data processing whereas TV receivers were used for entertainment purposes. However, from 1980s, computers as well as their monitors have been used by people for both entertainment as well as processing. Currently, TVs have some sort of computer functionality as well. The most common aspect ratio of TVs and computer monitors has changed to 16:9, from 4:3. Now, it is 16:10.