The laser printer works via the magic of static electricity.
When the laser printer receives data (file) to print, first it figures out what it looks like on page as an image, which is composed of millions of tiny dots.
Then, laser beam puts the image onto the drum inside the toner cartridge, and this builds up a pattern of static electricity on drum.
Next, the static electricity attracts toner from the toner cartridge onto drum.
Now paper comes, again, thanks of static electricity, the image is transferred onto the paper.
Finally, the paper runs through the heating unit, which is called fuser, and the toner image is melted, fused and bonded into paper.
By now, the data (file) is printed on page by the laser printer.