Laser printers use a laser beam that creates an image on a drum. The drum is covered with selenium. The electrical charge on the drum is modified when the beam touches it. When this happens the drum rolls over a container of toner and the charged parts of the drum electrostatically pick up the toner, which is dry ink. Lastly, the heat and pressure transfer the toner onto the printer paper. The ink is fused onto the paper.

Another name for laser printers is page printers. This name arose from the fact that the whole page transfers onto the drum prior to the application of the toner. Two other printers are called laser printers that don't use lasers; they use LCD's and LED's to transfer the image to the drum, though beyond this step, they perform like laser printers.

Advantages

- The laser printer is much faster because it prints a full page at once, but impact printers, ink jet and dot matrix printers print the streaming data as it comes in. They print each section directly and start and stop as they go along waiting for more information.
- The laser printer's speed enables it to more easily print text and graphics created using a computer program.
- It prints more exactly than other printers.
- It is more cost efficient concerning toner, whereas ink cartridges for other printers run out quicker and need replacement more often. More so when color is involved.
- Replacing the toner for a laser printer isn't messy like replacing ink for an ink jet printer cartridge.
- Laser printers include a copier and fax.

Though a laser printer costs more than a good ink jet printer, running the laser printer is cheaper because the toner last longer. The performance of laser printers continually improves and the price goes down. One of the main features of a laser printer is its resolution. That is the dots per inch it puts down. The low end resolutions are 300 dpi and the high end resolutions are 1,200. Some laser printers have resolution enhancement techniques. They can print a vast number of fonts.

Laser printers have an amount of RAM, which can be improved by putting memory boards in the expansion slots. Fonts can now be downloaded to the memory or RAM. The downloaded fonts are called soft fonts, which distinguishes them from the one on font cartridges called hard fonts.

Laser printers print graphics very well. It takes a higher quantity of RAM to print high-resolution graphics. Being non-impact printers, laser printers work quietly compared to daisy-wheel and dot-matrix printers.

There are two page descriptive languages for laser printers, which control how they print. These PDL's are the PLC language created by Hewlett-Packard and PostScript, which is the language for Apple printers. There are different versions of PLC; they aren't all compatible. PLC controlled printers and some that say they are compatible don't use HP font cartridges. PostScript is also used for desktop publishing systems.