A printer drum is a component of a laser printer that transfers the toner to the paper. It is a cylindrical metal or plastic piece that is coated with a photosensitive material. The drum is charged by a laser beam, which creates an electrostatic image of the document to be printed. The toner then sticks to the charged areas of the drum, and the drum rolls over the paper, transferring the toner to the paper and creating the printout.