Use the adverb far to mean "distant," "remote," or "at a geat distance away." When you see a ship far out at sea, it's so remote from where you are that you might soon need binoculars to catch a glimpse of it.
Far is used as both an adverb and an adjective, and it can mean both "distant in space," but also "distant in time," and "a lot." Therefore you can say, "Just look at us! We've come so far!" and also "You are far better at speaking French than I am." Old English had slightly different words for the adjective — feorr — and the adverb — feor.