A harness race is a type of horse racing in which the horses pull a two-wheeled cart called a sulky, driven by a jockey. The two main types of harness races are trotting and pacing. Trotting is a gait in which the horse moves its legs in diagonal pairs, while pacing is a gait in which the horse moves its legs on the same side at the same time. Both trotting and pacing are used in harness races.