Pari-Mutuel

A pool style wagering system, where all money input through betting is divided among those with winning tickets (save for various deductions by the track operators).

Workout

A workout is a timed sprint over varying distances prior to a race, meant to get a horse fit enough for competition.

Trifecta

A wager picking the first, second and third horses in the exact order. A trifecta box means paying more to ensure the horses can finish in any order in the top three spots.