A .pkg file is a package format used by Sony to distribute software on the PlayStation Network (PSN). In the context of console modification, PKG files are retail game backups, patches, or homebrew applications decrypted to run on consoles running custom firmware or specific web-based exploits (like the GoldHEN exploit). Retail PKGs vs. FPKGs (Fake PKGs)
It looks like you're asking for a blog-style or forum-style post about downloading PS4 games in "portable" or "extra quality" formats, specifically referencing (the standard installation format for PlayStation packages). pkg ps4 games extra quality download portable
Always use a Gigabit Ethernet cable instead of Wi-Fi to download files to your PC or storage server. PKG files are retail game backups