Ink jet printers printers work by a head passing over paper and making a series of small, different color dots. When the print job is done the tiny dots make up an image, or text. The closer the dots are to each other, the higher the quality of the print job. The distance of these dots from each other is measured in dpi, or dots per inch.

Laser printers work by using a laser beam to produce an image that eventually appears as printed output. The printed output is created as an array of fine dots. A laser being used in this fashion allows the printed output to be very high in quality. The print quality of a laser printer is similar to the quality used in magazines.

Thermal printers work much differently then most printers. Thermal printers, unlike most printers, do not print just with ink. Thermal ink jet printers print on heat sensitive paper and use a combination of ink and heat to print. Different colors are printed by a combination of ink and a certain temperature to burn in the ink to the paper. Thermal ink jet printers can print extremely high quality images and are excellent for printing digital images.

Dot matrix printers work, like most printers, by printing a series of dots. The big difference is that the dots are very large. Dot matrix is only good for printing text, and line art. It is almost impossible to print an image with a dot matrix printer. Dot matrix printing is being used much less because they are being outdated by modern, higher quality, printers. Dot matrix printing is useless to printing digital images.