In the PlayStation 3 ecosystem, a (Package File) is the standard installation format for digital content. Unlike folder-based backups (JB Folders), PKG files are the official Sony format used for:
PS3 PKG archives are a double-edged sword: a tool for digital preservation and a source of piracy. Use them wisely, ethically, and legally. Always dump your own games when possible, and support the developers who keep classic titles alive through remasters and backwards compatibility. ps3 pkg roms archive