Who's the Narrator?

Ask yourself that when you write your story. Even if it's an omniscient viewpoint who isn't a character, is that viewpoint speaking to contemporaries of the story, generations to come, modern audiences, or what? Comparing something to a helicopter, for example, is definitely out of place for Drizzt to say, but not necessarily for the narrator. What kind of references would the narrator use, or what actions would he applaud or condemn?