A process used in laser printers, some fax machines, analogue and digital photocopiers to transfer an image onto paper.
There are many variations on the process, but they all follow a basic concept.
A photoconductive drum or belt is electrostatically charged. Light from a laser, LED, or reflected from a mirror is directed onto the surface of the photoconductor, and causes the charge to dissipate to ground in the light-exposed areas, creating an electrostatic latent image.
Toner (a powdery black dry ink made from pigment and special polymers is then attracted to the photoconductor in much the same way as your hair is attracted to a charged balloon. A sheet of paper then passes close to the photoconductor, and a strong electrostatic charge is used to transfer the toner image onto the paper.
The paper then passes into a fuser, a device which uses heat and pressure to permanently fuse the toner onto the page.