What does it mean to learn to talk early?

Sometimes early talking indicates high intelligence, but not necessarily of the child. It may just mean that an intelligent mother can make sense out of her child's "babbling" sooner than most mothers can. Of course this early feedback stimulates the child to produce more speech, which stimulates more maternal recognition, and all this interaction is known to favor giftedness. Some late talkers are highly intelligent, too. Einstein didn't talk till he was five.