The split screen feature is commonly used in non-networked, also known as couch co-op, video games with multiplayer options.
In its most easily understood form, a split screen for a multiplayer video game is an audiovisual output device (usually a standard television for video game consoles) where the display has been divided into 2-4 equally sized areas (depending on number of players) so that the players can explore different areas simultaneously without being close to each other.
In competitive split-screen games, it is customarily considered cheating to look at another player's screen section to gain an advantage.
The addition of four controller ports on home consoles also ushered in more four-way split screen games, with Mario Kart 64 and Goldeneye 007 on the Nintendo 64 being two well known examples.
On home machines, especially in the first and third person shooter genres, multiplayer is now more common over a network or the internet rather than locally with split screen.