Everyone says "dependent clauses are the ones that can't stand alone." I think that's a wrong interpretation of subordinate clauses. By that logic, even independent clauses can't stand alone. Let me explain:
"Rob went to the restaurant because he was hungry."
Of course, "because he was hungry" can't stand alone. But let's look a coordinating conjunction and do the same thing:
"Rob went to the jungle, and he got lost."
Can "and he got lost" stand alone? No. If you leave out the conjunctions, both sentences can stand alone.
So why do they say that?
In my opinion the difference is best put like this: coordinating conjunctions give more weight to one of the clauses, and that's why they are called "independent clauses". Subordinate conjunctions do the opposite.