A Straight Bet -- This would be a bet for $2 or more on one horse to WIN, PLACE or SHOW, or a two-horse exacta, three-hourse trifecta, four-horse superfecta, two horse Daily Double.
A Wheel -- In a WHEEL, you choose one or more horses in more than one position in an exotic bet. The amount of money bet depends upon the amount of horses in each position on the wheel.
A Box -- In a BOX bet, you choose two (in exactas) or more horses and cover every possible finishing combination in a bet. The Box is the most expensive investment of the three bets.