If you enjoy reading stories about the sea and sailing ships, you understand that, to do that, you need a special vocabulary. Read Joseph Conrad tales or "Moby-Dick," for example, and you need to know that petty, poop, port and prop have specific meanings quite apart from what they might conjure up in another context. You need to understand scuttle, butt and scuttle butt (and, yes, the notion of scuttle butt as rumor started on board ship).
Similarly, when you move overseas you may need some new vocabulary. Here, following, are a few important definitions for expats.