TV Guide has been the name for many different things over the years. It was mostly a magazine until the mid-90s, when News Corp (its parent company) and TCI started the TV Guide On Screen channel, which was a scrolling channel guide much like the Prevue Channel. Not much is known about this channel, as there is very little documentation of it online. TCI and UVSG also worked together to write TV Guide On Screen, one of the first interactive program guides for (General Instrument, now Motorola-based) digital cable STBs. This was later acquired by UVSG in its entirety and renamed Prevue Interactive, and is currently known as TV Guide Interactive or i-Guide.
The current TV Guide On Screen product is a completely unrelated guide that is built-in to various TVs and gets program data from information digitally encoded into broadcast TV stations. Before digital TV began catching on, it received its data from the VBI of broadcast TV stations.
In 1999, United Video Satellite Group acquired TV Guide from News Corp and renamed itself to TV Guide Inc. See United Video Satellite Group for more information.