Prestel was internet before internet; Camden before Shoreditch, Twin Peaks before Lost, if you will.
Launched in 1979 by the Post Office (who looked after the phone lines back then), Prestel gave thousands of people a glimpse of their connected futures by offering online shopping, train timetables and internet banking directly through your TV.
Prestel was able to achieve such science fiction by utilising a piece of tech called Viewdata, an information retrieval service in which a subscriber could access a remote database via common carrier channel, request data and receive said data on a video display over a separate channel. If you don’t speak fluent jargon then it’s best to think of Prestel as an interactive, 2-way Teletext, albeit with far more scope.
Whilst superficially similar to Teletext, Prestel ran across the phone network, in comparison to Teletext which was transmitted across the television signal. You plugged a terminal into your television set and it connected to a database of information via a telephone line. The idea was that computers cost way too much dollar back then, so by delivering content online through the TV (which everybody had) was a somewhat logical way to get consumers online.