ISOs are image files that contain the data from a CD or DVD, essentially a copy of the game or software. For the PS1, these files are typically in the format of .iso and can be used to play games on emulators or to burn new copies of the game.
: A PlayStation 2 launcher that allows you to play PS1 games on a PS2 via USB, HDD, or network. It is often integrated with OPL (Open PS2 Loader). Common File Formats ps1 iso espa%C3%B1ol %C3%B3ps