Editing Fax (section)

{{short description|Method of transmitting images, often of documents}}
{{Redirect|T.30||T30 (disambiguation)|and|Fax (disambiguation)}}
[[Image:Samsung SF-3100 Inkjet Fax Machine.jpg|thumb|upright=1.2|This fax machine from 1999 used relatively new [[inkjet printing]] technology on normal paper.]]
[[Image:Panasonic KX-F90.jpg|thumb|upright=1.2|Like many fax machines, this 1990 model used [[thermal printing]] on relatively expensive [[thermal paper]] which came in rolls. The roll was inserted into a compartment in the machine.]]

'''Fax''' (short for '''facsimile'''), sometimes called '''telecopying''' or '''telefax''' (short for '''telefacsimile'''), is the [[telephone|telephonic]] transmission of scanned printed material (both text and images), normally to a telephone number connected to a printer or other output device. The original document is scanned with a '''fax machine''' (or a '''telecopier'''), which processes the contents (text or images) as a single fixed graphic image, converting it into a [[bitmap]], and then transmitting it through the telephone system in the form of audio-frequency tones. The receiving fax machine interprets the tones and reconstructs the image, printing a paper copy.<ref>{{cite web| url=http://searchnetworking.techtarget.com/definition/fax| title=What is fax?| last=Rouse| first=Margaret |date=June 2006 |publisher=SearchNetworking |access-date=25 July 2012}}</ref> Early systems used direct conversions of image darkness to audio tone in a continuous or analog manner. Since the 1980s, most machines transmit an audio-encoded digital representation of the page, using [[data compression]] to transmit areas that are all-white or all-black, more quickly. 

Initially a niche product, fax machines became ubiquitous in offices in the 1980s and 1990s.<ref>{{Cite book |last1=Shapiro |first1=Carl |url=https://books.google.com/books?id=aE_J4Iv_PVEC |title=Information Rules: A Strategic Guide to the Network Economy |last2=Varian |first2=Hal R. |date=1999 |publisher=Harvard Business Press |isbn=978-0-87584-863-1 |pages=13 |language=en}}</ref> However, they have largely been rendered obsolete by [[Internet]]-based technologies such as [[email]] and the [[World Wide Web]], but are still used in some medical administration and law enforcement settings.<ref name=":0" />