Systems that provide electronic transmission of ordinary documents, incuding drawings, photographs, and maps. The original document is scanned at
the sending station, converted into an analog or digital representation, and
sent over a communication channel to the receiving station, which constructs a
duplicate image on paper; this image is referred to as a facsimile. Early
facsimile systems were exclusively analog, but new systems have been designed
that use digital techniques for data encoding and transmission.