You're getting yourself all confused, there are different region codes for different disc formats, just because a device uses one of these formats doesn't necessarily mean they all share the same type of region lock.
For movies (DVD) there are 6 regions, Bluray (movies) there are 3 regions.
Consoles/PCs might use these disc formats, but they don't use the same region locks. Games for consoles generally have 3 regions, PAL, NTSC/U & NTSC/J which is based moreso on the analogue TV signal these regions used to use.
There is no region locking for PC games as far as I'm aware. It's a universal worldwide format, the only locking might be to do with multiplayer servers, etc, but that wouldn't stop you from playing the game.
Wikipedia probably explains it a little better.