The Action: An exacta requires bettors to correctly predict the first- and second-place finishers in a given race. When you play an exacta, you only win if the horses you pick are first and second. If your horses finish first and third, for example, that won't cut it.
While exactas and other exotic bets (in which bettors must predict the finish of more than just one horse) are riskier than basic win, place and show bets, exactas often pay a lot more money than those basic bets.