Monitors are a very important part of today's PC. Can you think of anything that you could do with your computer without a monitor?. If you cannot think of anything, you are not the only one. Yet, believe it or not, early computers did not have one. Instead of displaying information on the screen, there would be a sequence of LEDs (Light Emitting Diodes). This is basically just a light that could be turned on or off. When the LED is on, this would symbolize a binary "one", while off, this would symbolize a binary "zero". The other way to get processed data from the computer would be through a printer. This method was faster than the LED method, but you would have to print an enormous amount of information, instead of reading it all from a monitor.

The LED and printer method of output limited what people could do with a computer. It made the computer very hard to operate and understand. Also, operations such as word processing, or even playing games, were impossible.

When monitors came, it made it much easier for typical people to use computers. The most common type of monitor was one which included a CRT tube. It was very heavy, took up space, and consumed a lot of electricity, while only being able to produce two colors for us to see. Slowly, the 2-color limit changed into a 16-color limit, then to a 256-color limit. Now monitors produce more colors than our eye can decipher. Also, instead of focusing on the amount of colors the monitor can display, monitor producers are focusing on other features, such as cost, efficiency, image quality, monitor display size, flatness of the monitor display (the flatter the better, most CRTs are convex), weight, as well as volume.

Although TVs work similarly to CRT Monitors, they produce less detail, and irritate the eyes more.
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While CRT monitors can be developed to have some of the features named above, there are new technologies that have fully taken care of some of these problems. One of these new technologies is the LCD Monitor. Some of its advantages are that it is very light, has a much smaller area than CRTs and is extremely efficient.

As you can see, LCD monitors are much smaller, and lighter.
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LCD Monitors are not perfect though. They also have their own disadvantages, including the fact that they are 3-4 times more expensive than CRT Monitors.

Both the CRT and the LCD Monitors are covered in depth later in the Display section, but first we need to know how both of the monitors produce the different colors for the user to see.