Horse racing is a popular sport with rules, traditions, and events that vary by country. The sport has been influenced by technological advances, but it has also adapted many of these innovations for the safety and welfare of horses and jockeys. Horses are now subject to a variety of advanced tests and treatments, including thermal imaging cameras, MRI scanners, and 3D printing to produce casts and splints.

A horse race is a competition between two or more horses, typically on flat ground and over a distance of at least a mile. The goal is to win the race by crossing a finish line before all other competitors. The winner is awarded a set amount of prize money, depending on the type of race. The first place finisher wins the most, while the second and third place winners receive less prize money. A large number of horse races are held around the world each year, and most countries have their own national championship series. The three American classics, the Belmont Stakes, Preakness Stakes, and Kentucky Derby, are known as the Triple Crown of Thoroughbred horse racing.

The earliest horse races were intended to showcase the top speed of a given horse to potential buyers, and were often held on open fields or roads. During these early days, the winners were not awarded any prize money, but as field sizes increased, and professional riders (jockeys) became more commonplace, a second place prize was offered, and later a third place prize as well.

In order for a horse to be eligible to compete in a race, it must have a pedigree that demonstrates its breeding and racing history. This means that its sire and dam must both be purebred individuals of the breed it is racing. Most modern flat horse races are open to horses of all ages, but some are restricted to horses between the ages of two and five. This is because most horses reach their peak performance by age three, and escalating purses and breeding fees have led to fewer races being run with older horses.

In addition to expanding the number of available races, technological improvements in pari-mutuel betting have dramatically increased the sport’s popularity. Until 1984, bets were tallied manually, but once the system was computerized, turnover and attendance significantly increased. The introduction of color television in the 1970s and later of live televised racing has further broadened the appeal of the sport.