These are the most common output devices for displaying the results of processing carried out by the computer
The VDU (Computer Monitor or Screen)
The VDU (Visual Display Unit) is the computer screen used for outputting information in a way that we can understand. The computer works in binary code (a series of on/off impulses).
FLAT SCREEN MONITORS
Traditional computer monitors are based on the same technology which is used within a television screen. More recently flat screen monitors have become available. These take up less room on the desk and use less energy than the traditional more bulky monitors.
Be aware that the screen size that is quoted for the monitors is not the vertical or horizontal size, but it is the diagonal measurement across the screen. When buying a monitor you should ask for the visible viewing area of the screen.
GRAPHICS FOR GAMES
Many games require advanced graphics cards to be installed within your computer to make them run. They contain their own CPU which is dedicated purely to displaying the graphics on your screen. Recent PCs usually have this capability built in.
Laser printers produce high quality at high speed. They are called laser printers because of the fact that they contain a small laser within them.
COLOUR LASER PRINTERS
Originally, most laser printers would only print in black and white (mono). More recently colour printers have dropped in price and are in more common use. Many of these produce excellent results, but you should be aware of the fact that the cost per page especially if you are using a lot of colour on a page can be very high compared to that of printing in black and white.
Inkjet printers work by using tiny jets to spray ink onto the paper. They produce a quality comparable to that of laser printers and are very quiet in use, though laser printers are still faster. Inkjet printers are ideal for use where speed is not a high priority, such as a small office or the home.
DOT MATRIX PRINTERS
Dot Matrix printers work by firing a row of pins through an ink ribbon onto the paper. The more pins the print head has the higher the quality of the print, most modern printers have 24 pins. Unfortunately, these printers can be very noisy and dont produce a very good quality of print especially when printing graphics. As a result, the inkjet printer has largely replaced the dot matrix printer.
Most printers have their own memory chips. If you are printing large graphics, pictures for example and you want the best quality output from your printer then you should consider adding more memory for your printer. This can speed up the rate of at which you can print pages.
A plotter is a device similar to a printer, but normally allows you to print larger images. They are used widely in the design and research sector.
Most computers have the facility to add a pair of speakers to the system unit, in some cases the monitor may have speakers built directly into the unit.