This is a standard Google "dork" (advanced search operator). It specifically targets web servers, such as Apache or Nginx, that have directory listing enabled. These servers display a list of files rather than a formatted webpage, making them efficient for bulk downloading.
A PS3 ISO file is a digital copy of a PS3 game, stored in a single file with a .iso extension. These files contain the entire game data, including the game itself, artwork, and other metadata. ISO files are essentially a snapshot of a PS3 game's disc, allowing users to play the game without needing the physical disc. index of ps3 iso verified