Dot matrix printers create letters and graphics by striking an inked ribbon with a column of small wires. This is the type of printer that uses the continuous feed paper on tractor feeders - great for making banners. Ink-Jet printers produce characters and graphics by spraying ink onto paper. The print head is a matrix of fine spray nozzles. Patterns are formed by activating selected nozzles.
Laser printers use the same technology as duplicating machines.
A laser charges a pattern of particles on a drum which picks up a powdery black substance called toner. Keyboard and mouse are the two main input devices. Monitor and printer are the two main output devices. A process can be anything that changes the data or performs an action, such as adding, subtracting, or putting letters on a page. This includes the memory chip inside the computer, floppy disk and CD-ROMs.