The phrase refers to a specific file format associated with the digital distribution of a particular video game. It signifies a disk image, essentially a complete archive of the game’s data, designed for use with emulators or for archival purposes. As an example, it is the file type one might look for to play the game on a PC instead of its original console.
Its significance lies in its ability to preserve and distribute the game beyond its original platform. It offers a way to experience the game on modern hardware, ensuring access even if the original console is no longer functional or available. Historically, it has played a vital role in game preservation and accessibility.