Computer devices that are not part of the essential computer (i.e. the memory and microprocessor). Peripheral devices can be external and internal.
Devices that print text or illustrations on paper. There are many different types of printers.
Devices that can read text or illustrations printed on paper and translate the information into a form the computer can use. A scanner works by digitizing an image — dividing it into a grid of boxes and representing each box with either a zero or a one, depending on whether the box is filled in.