In computing, a printer is a peripheral device which makes a persistent representation of graphics or text, usually on paper. While most output is human-readable, bar code printers are an example of expanded use for printers. A printer is a person or company whose job is printing things such as books. The manuscript had already been sent off to the printers. Printers are a type of computer peripheral that fall into two broad categories. 2D prints text and graphics onto paper and 3D printers create physical objects.