Editing Online and offline (section)

==History==
During the 19th century, the term ''on line'' was commonly used in both the [[Rail transport|railroad]] and [[Telegraphy|telegraph]] industries. For railroads, a [[Signalling control|signal box]] would send messages down the line (track), via a telegraph line (cable), indicating the track's status: ''Train on line'' or ''Line clear''.<ref>{{cite book |url=https://archive.org/details/greatbritainrai00tradgoog |quote=train on line. |title=Great Britain Railways: Accidents. Court of Inquiry Reports |author=Great Britain Board of Trade |year=1874 |page=[https://archive.org/details/greatbritainrai00tradgoog/page/n174 33] |access-date=8 April 2015}}</ref> [[Lineworker|Telegraph linemen]] would refer to sending current through a line as ''direct on line'' or ''battery on line'';<ref>{{cite book |url=https://books.google.com/books?id=A4A3AQAAMAAJ&q=%22on+line%22+telegraph&pg=PA172 |title=Journal of the Society of Telegraph Engineers: Including Original Communications on Telegraphy and Electrical Science, Volume 8 |author=Society of Telegraph Engineers |year=1879 |page=172 |access-date=8 April 2015}}</ref> or they may refer to a problem with the circuit as being ''on line'', as opposed to the power source or end-point equipment.<ref>{{cite book |url=https://books.google.com/books?id=yxgAAAAAQAAJ&q=%22on+line%22+telegraph+battery&pg=PA47 |title=The practical telegraphist and guide to the telegraph service |author=William Lynd |year=1885 |page=47 |access-date=8 April 2015}}</ref>

Since at least 1950, in [[computing]], the terms ''on-line'' and ''off-line'' have been used to refer to whether machines, including [[computer|computers]] and [[peripheral|peripheral devices]], are connected or not.<ref name=stiffler>{{cite book |author1=The staff of Engineering Research Associates, Inc. |date=1950 |author-link=Engineering Research Associates |editor1-last=Stiffler |editor1-first=W. W. |title=High-Speed Computing Devices |publisher=McGraw Hill Book Company, Inc. |url=https://archive.org/details/bitsavers_eraHighSpe950_30096406/ |accessdate=2022-09-02 |page=[https://archive.org/details/bitsavers_eraHighSpe950_30096406/page/n19 19]}}</ref> Here is an excerpt from the 1950 book ''High-Speed Computing Devices'':{{r|stiffler}}

: The use of automatic computing equipment for large-scale reduction of data will be strikingly successful only if means are provided for the automatic transcription of these data to a form suitable for automatic entry into the machine. For some applications, of which the most prominent are those in which the reduced data are used to control the process being measured, the input must be developed for ''on-line'' operation. In on-line operation the input is communicated directly and without delay to the data-reduction device. For other applications, ''off-line'' operation, involving automatic transcription of data in a form suitable for later introduction to the machine, may be tolerated. These requirements may be compared with [[teletype|teleprinter]] operating requirements. For example, some teletype machines operate on line. Their operators are in instantaneous communication. Other teletype machines are operated off line, through the intervention of [[punched tape|punched paper tape]]. The message is preserved by means of holes punched in the tape and is transmitted later by feeding the tape to another machine.