The focus on PKG files today is largely driven by the desire to preserve titles that may no longer be available for purchase as digital storefronts age [.5.8]. By converting physical media into PKG or ISO formats, enthusiasts ensure that the PS3’s vast library remains playable on original hardware and emulators like for years to come [.5.6, .5.27].
It works like an installer: you place it on a USB drive or internal HDD, then install it via the PS3’s “Install Package Files” menu (available only on custom firmware or developer units). Ps3 Pkg File Download