An impact printer is a type of printer that operates by striking a metal or plastic head against an ink ribbon. The ink ribbon is pressed against the paper, marking the page with the appropriate character, dot, line, or symbol. Common examples of impact printers include dot matrix, daisy-wheel printers, and ball printers.
Dot matrix printers work by striking a grid of pins against a ribbon. Different characters are printed by using different pin combinations. Daisy-wheel printers use a circular wheel with "petals" that each have a different character or symbol on the end. In order to print each character, the wheel spins to the appropriate petal and a hammer strikes the petal against the ribbon and the page. Similarly, ball printers use a spherical ball with raised characters on the outside. The ball spins to each character before printing it on the page.
While impact printers still have some uses (such as printing carbon copies), most printers are now non-impact printers. These printers, such as laser and inkjet printers are much quieter than impact printers and can print more detailed images.