A bridle is a piece of equipment used to direct a horse. As defined in the Oxford English Dictionary, the "bridle" includes both the headstall that holds a bit that goes in the mouth of a horse, and the reins that are attached to the bit. It provides additional control and communication through rein pressure.
A hunt seat style English bridle
Western show bridle
The crownpiece runs over the horse's poll, and the browband across the forehead. The cheekpieces run down the sides of the horse's face.
A double bridle, using two bits
The horse is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of Equus ferus. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature, close to Eohippus, into the large, single-toed animal of today. Humans began domesticating horses around 4000 BCE, and their domestication is believed to have been widespread by 3000 BCE. Horses in the subspecies caballus are domesticated, although some domesticated populations live in the wild as feral horses. These feral populations are not true wild horses, which are horses that never have been domesticated and historically linked to the megafauna category of species. There is an extensive, specialized vocabulary used to describe equine-related concepts, covering everything from anatomy to life stages, size, colors, markings, breeds, locomotion, and behavior.
Horse
Points of a horse
Size varies greatly among horse breeds, as with this full-sized horse and small pony.
Bay (left) and chestnut (sometimes called "sorrel") are two of the most common coat colors, seen in almost all breeds.