When you download a game from the PlayStation Store, your console is actually downloading a PKG file in the background. Official PKG files are encrypted, signed by Sony, and designed to install only on legitimate, unmodified PS4 systems.
An on-console app store that allows users to browse and install over 2,000 pieces of content directly to their PS4. How to Install PKG Games
You cannot simply plug a USB drive into a brand-new PS4 and start installing PKG files. The console must be "exploited" or modded. Here is the basic checklist:
