Printers can serve as standalone equipment as well as a computer accessory. It generally takes input from the computer and generates output on a paper. It produces output in the form of graphics and text. There are mainly two categories of printers – Impact printers and Non-impact printers. Impact printer makes direct contact with paper. It presses inked ribbon using pins and hammers to produce print on paper. Non-impact papers do not use a striking device and are much quieter.
Dot Matrix printers: This printer uses pins to form patters of dots on paper to produce characters. A 24 dot matrix printer forms more dots than its 9 dot matrix peer.
Daisy-wheel printers: The printing mechanism works like a daisy where each petal contains a character. The characters get printed on paper, when a hammer presses against the ribbon.
Band printers: It uses a band which generates character upon paper. The steel band comes with five sections of 48 characters each.
Line printers: Line printers are a line at a time printer instead of character at a time type. It can print 1000-6000 lines per minute. Chain, drum and band printers are line printers too.
Chain printers: Wrapped around two pulleys is a chain that prints characters in a chain printer. There is a hammer allocated for each and every print position.
Drum printers: It uses a central drum that raises characters against band on the surface. It offers 80-132 print positions, while rotating at rapid speed.
Ink-jet printers: It uses the principle of dot matrix printer. But it uses tiny droplets of ink to form the dots.
Laser printers: Like a photocopy machine, it directs laser beams at mirror that directs it to drum. As paper goes by the drum, it uses a toner to transform the print to paper.