Printers are output devices used to print documents on paper, film or other media. Printers make it easier to read documents by producing a physical copy that can be kept for future reference. Printers can generally be divided into two categories of output methods: impact and non-impact. Impact printers include dot matrix, daisy wheel and line printers. These types of printers produce images by striking a ribbon with pins, needles or wheels. Non-impact printers include inkjet, laser, thermal and photo printers. These types of printers release a steady stream of ink or toner onto the page to produce a printed image.