I'm sorry but could you guys simply what you just said a bit. I amn't the most technical person so I didn't understand all of what you just said. :c
Essentially there's encoding types for 2 different kinds of hard drives, 1 that BIOS can read (windows and linux operating systems) and 1 that the macs can read. If you were to plug a hard drive used with windows into a mac, it wouldn't read because the files are encoded in a way that only windows and linux could read them, and vice versa with the mac style encoded devices.
Now there's partitions, which is basically splitting a hard drive into multiple pieces, so you could dual boot operating systems. If you were to make a partition for mac encoded files, and a partition for bios encoded files, you could do what you're asking.
I can't really simplify it much more :/