A printer is one of the output devices of a computer, used to print the results of computer processing onto relevant media. There are three indicators to measure the quality of a printer: print resolution, print speed, and noise. There are many types of printers, classified into impact printers and non impact printers based on whether the printing element has a striking action on the paper. According to the printing character structure, it can be divided into full form character printers and dot matrix character printers. Divided into string printers and line printers by forming a line of characters on paper. According to the technology used, printers can be classified into cylindrical, spherical, inkjet, thermal, laser, electrostatic, magnetic, LED, and other types.