Questions about crafting

I am fairly new to WOW. I was introduced through a turtle WOW server and decided to give the full game a try, so I have very little (maybe 15 or so hours) experience with Classic and Cataclysm. I am trying to do leatherworking in Battle for Azeroth, and I noticed that I have leather working for different regions in the game.

My question is, do these different regions offer different leatherworking skills that have to be leveled separately or is it just access to different recipes? I have tried looking and couldn't find anything that answered that question.