Learn more about Rein
Reins are a type of horse tack. A bridle is an arrangement of straps around the horse's head used for riding and driving the animal. A bridle contains a bit (a piece of metal that is placed in the horse's mouth) attached to reins. Reins are leather straps or rope attached to the outer ends of a bit that extend to the rider's or driver's hands, allowing them to give rein aids.
 Animal riding
Main article: riding aids
Reins are used to communicate to the horse or other riding animal. With the reins you can bend the neck and encourage turning. But a rider must also use leg cues and body weight. When a rider squeezes her/his leg, the horse responds by moving away from the pressure. The reins can be used to warn the horse that you are about to turn. The sides of a horse's mouth are sensitive, so pulling on the reins pulls the bit (a solid mouth piece, usually in metal), which then pulls the horse's head to the side.
Reins are also used to stop a horse. By gently applying pressure to the reins in a backward motion and sitting against the horse's movement for a short time, you can stop a horse completely or cause the horse to walk backward.
 Wagon drawing
On some types of harnesses there might be supporting rings to carry the reins over the animal's back. When pairs of equines are used in drawing a wagon or coach it is usual for the outer side of each pair to be connected to the reins and for the inside of the bits to be connected by a short bridging strap or rope. The driver carries "four-in-hand" or "six-in-hand" being the number of reins connecting to the pairs.
A single rein may be attached to a halter to lead or guide the horse in a circle for training purposes or to lead a packhorse.
Types of reins include: