Digital installers originally used by the PlayStation Store.

Virtua Tennis 4 PKGs are highly sought after because they allow for faster loading times directly from the HDD compared to physical Blu-ray discs. How to Install PS3 PKG Files

When users look for a "PKG" file, they are usually looking for a digital package format that can be installed on a PlayStation 3 running or PS3HEN .

Often required alongside PKGs to "activate" the game license on homebrew systems.