The sending part of a machine is more like a computer scanner. It comes with a CCD that scans the document, one line at a time. It scans only in black and white. Then, these black and white lines are transmitted in a special kind of electric pulse down the phone line. The phone line then transmits this information instantly to facsimile machines at the receiver’s end. It receives the electric pulses and uses them for controlling the printer. If the receiver hears a “black”, it draws a small black dot on the paper. When it hears a “white”, it slightly moves along, leaving white space on the page.