the Electronic Program Guide, as used in digital television
systems delivered by satellite
, or even regular terrestrial broadcasts - eg Sky Digital
in the UK.
Features vary from system to system, but usually you will be able to bring up a grid with all the available channels, and the programs being shown for anywhere up to a week. Information on each show can be obtained by selecting it and pressing an info key, and a reminder or timer can be set for a future program.
While watching a program, information on the current show can be obtained by pressing the info key, and schedule information showing the name and time of the present and next show can be superimposed on the picture. It may also be possible to see what's on other channels through this features, or what's on at other times of day.
More advanced systems will allow you to search through the schedules by keying in the program's name to see when it is next on, others may have an alphabetical list of all the shows to scroll through.
EPGs can often sort channels by genre too, enabling you to see what's on only sports channels, for example.
In theory, you shouldn't ever need to buy a TV Guide again.