An ISO file is a type of disk image file that contains the contents of a CD or DVD, in this case, the FIFA 17 game disc. Downloading a FIFA 17 ISO file for PS3 might seem like an easy way to obtain the game, but it's essential to understand the risks involved. ISO files can be used to play games on consoles or computers, but they may not always work as expected, and their use can be linked to piracy.