Editing Videotex (section)

==Definitions==

Definitions of Videotex and associated terms.<ref>''Videotex: the new television-telephone information services'', by R. Woolfe, published by Heyden & Son Ltd, London, 1980, {{ISBN|0-85501-493-8}}</ref> These definitions were written in 1980 so some names may be out of date.

* Videotex: A two-way interactive service. The term was coined by [[CCITT]] and emphasizes information retrieved with the capability of displaying pages of text and pictorial material on the screens of adapted TVs.
* [[Viewdata]]: An alternative term to videotex, used in particular by the [[General Post Office|British Post Office]] and generally in Britain and the USA.  Elsewhere, the term videotex is preferred.  Viewdata was coined by the BPO in the early 1970s, but found to be unacceptable as a trade name, hence its use as a generic.
* [[Teletext]]: One-way broadcast information services for displaying pages of text and pictorial material on the screens of adapted TVs.  A limited choice of information pages is continuously cycled at the broadcasting station.  By means of a keypad, a user can select one page at a time for display from the cycle.  The information is transmitted in digital form usually using spare capacity in the broadcast TV signal.  Careful design can ensure that there is no interference with the normal TV picture.  Alternatively, it can use the full capacity of a dedicated channel.  Compared with two-way videotex, teletext is inherently more limited, though generally less costly.
* [[Teletex]]: A text communication standard for communicating word processors and similar terminals combining the facilities of office typewriters and text editing.
* [[Ceefax]] ("See facts"): The [[BBC]]'s name for its public teletext service available on two TV channels using spare capacity.
* [[ORACLE (teletext)|Oracle]] ("Optional recognition of coded line electronics"): The name of the [[Independent Broadcasting Authority|IBA's]] equivalent teletext service.
* [[Bildschirmtext]], DataVision, Bulletin, [[Captain (videotex)|Captain]], [[Teletel]], [[Prestel]], [[Viewtron]], etc.:  The proprietary names for specific videotex implementations.