headgear by which a horse or other burden-bearing or pulling animal is governed, consisting of bit, headstall, and reins. The bit is a horizontal metal bar placed in the animal's mouth and held in place by the headstall, a set of straps over and around the head. Component bits of bone and antler have been recovered from bridles in use in the Bronze Age, about 3000 BC.

The reins, lines held in the hand of the rider or driver, are connected to either side of the bit so that a tug on either side turns the animal in that direction. The headstall sometimes includes blinkers—leather flaps that inhibit side vision to keep the animal from being frightened or distracted.