The PS4 is in the twilight of its life, gradually being replaced by the PS5 on a wider scale. However, the PS4's usefulness doesn't end with games.
To format a hard drive before you start using it in Windows, use the Disk Management utility; on a Mac, use Disk Utility.
The PS5 has 825GB of storage space, but you can only use 667.2GB of it — unless you use an external hard drive.