Horse racing is an equestrian sport that has been practiced over the centuries; the chariot races of Roman times are an early example, as is the contest of the steeds of the god Odin and the giant Hrungnir in Norse mythology. It is often inextricably associated with gambling. The common sobriquet for Thoroughbred horse racing is The Sport of Kings
One of the principal forms of horse racing, which is popular in many parts of the world, is Thoroughbred racing. Harness racing is also popular in Australia, New Zealand, the eastern United States and more popular than Thoroughbred racing in Canada and parts of Europe. Quarter horse racing is also popular in the western United States and Florida. Racing with purebred Arabian horses exists in several states in the United States, as well as in most of Europe and the Middle East. This form of racing is known as endurance racing.

The different types of racing all concern different breeds of horses. The Thoroughbred races moderate distances at very fast paces. The Quarter Horse is involved in short distance sprinting while the Arabian is involved in endurance racing. These three different breeds of horses possess different muscle structures that make them suitable for their type of racing. These horses race on various track surfaces ranging from dirt to synthetic polytrack.

The breeding, training and racing of horses in many countries is now a significant economic activity as, to a greater extent, is the gambling industry which is largely supported by it. The time invested in training these horses is extensive and varies according to the type of race the horse is involved in. Exceptional horses can win millions of dollars and might make millions more by providing stud services, such as horse breeding.
History

Horse racing in the United States and on the North American continent dates back to the establishment of another course named Newmarket -- on the Salisbury Plains section of what is now known as the Hempstead Plains of Long Island, New York in 1665. This first racing meet in North America was supervised by New York's colonial governor,Richard Nicolls. The area is now occupied by the present Nassau County, New York region of Greater Westbury and East Garden City. The South Westbury section is also (appropriately) known as Salisbury.