Learn how a fax machine transmits graphics and text over phone lines.
Telefacsimile (also telefax or facsimile or fax) transmits graphic and textual information from one location to another through telephone lines. A transmitting machine uses either a digital or analog scanner to convert the black and white representations of the image into electrical signals that are transmitted through the telephone lines to a designated receiving machine. The receiving unit converts the transmission back to an image of the original and prints it.
In its broadest definition, a facsimile terminal is simply a copier equipped to transmit and receive graphics images.