A small chip that can be used in a Playstation, Playstation 2 or XBox. It allows you to play Import Games and Illegally Copied games by tricking the game system you have an authentic game.
A chip which, if installed into a videogame console, allows it to play illegal backups of games, or homebrew that could otherwise not be compatible with the console. Their use in common in countries with do not penalize the use of illegal backups (maybe because said countries don't manufacture videogames.)