Output is anything that comes out of a computer. Output can be meaningful information and can appear in a variety of forms - as binary numbers, as characters, as pictures and as printed pages.

Monitor


This is also known as Video Display Unit (VDU). It is used to display a wide variety of information, such as text, graphics, video, animations, icons, etc.

Printer

Printer is a device that prints text or illustrations on paper and in many cases on transparencies and other media. Printed information, which exists physically is called hard copy.

There are many different types of printers - for example, Dot Matrix Printer, Inkjet Printer, Laser Printer and Plotters. These printers are discussed below.

(a) Dot Matrix Printer


Dot-matrix printers use a set of closely spaced pins and a ribbon to print letters or other characters on a page. These printers actually strike the page to print a character, much like a typewriter. Dot-matrix printers vary in terms of speed and the number of pins they have. They can run at a speed anywhere between 50 and 500 CPS (Characters Per Second). The number of pins, which can vary between 9 to 24, determines the quality of the print job. Dot matrix printers are commonly used for printing invoices, purchase orders, shipping forms, labels, and other multi-part forms.

(b) Inkjet Printer


Ink-jets printers spray ionized tiny drops of ink onto a page to create an image through nozzles. Almost all ink-jets offer a color option as standard, in varying degrees of resolution.

Ink-jet printers are capable of producing high quality print which almost matches the quality of a laser printer. A standard ink-jet printer has a resolution of 300 dots per inch. These are silent printer as they do not make much noise while printing a document.

(c) Laser Printer


Laser printers operate by shining a laser beam to produce an image on a drum. The drum is then rolled through toner (ink in form of powder), and the electrically charged portions of the drum pick up ink. Finally, using a combination of heat and pressure, the ink on the drum is transferred onto the page. Laser printers print very fast, and the toner cartridges work a long time. Colour laser printers use the same toner - based printing process as black and white (B/W) laser printer, except that they combine four different toner colors. These are the most high quality printers.

Plotter


Plotters are large-scale printers that are very accurate at reproducing line drawings. They are commonly used for technical drawings such as engineering drawings or architectural blueprints. The two basic types of plotter are called flatbed plotters and drum plotters. Flatbed plotters are horizontally aligned with a flat surface to which a piece of paper is attached. The paper remains stationary and the printer moves pens across the paper to draw the image. Drum plotters, also called upright plotters, are vertically positioned. They have a drum that the paper rolls on. Drum plotters usually make more noise and are more compact than flatbed plotters.