elements

The bridle consists of the following elements:

Crownpiece: The crownpiece, headstall (US) or headpiece (UK) goes over the horse's head just behind the animal's ears, at the poll. It is the main strap that holds the remaining parts of the bridle in place.

Cheekpieces: On most bridles, two cheekpieces attach to either side of the crownpiece and run down the side of the horse's face, along the cheekbone and attach to the bit rings. On some designs, the crownpiece is a longer strap that includes the right cheek and crownpiece as a single unit and only a left side cheekpiece is added.

Throatlatch: the throatlatch (US) or throatlash (UK) is usually part of the same piece of leather as the crownpiece. It runs from the horse's right ear, under the horse's throatlatch, and attaches below the left ear. The main purpose of the throatlatch is to prevent the bridle from coming off over the horse's head, which can occur if the horse rubs its head on an object, or if the bit is low in the horse's mouth and tightened reins raise it up, loosening the cheeks.

Browband: The crownpiece runs through the browband. The browband runs from just under one ear of the horse, across the forehead, to just under the other ear. It prevents the bridle from sliding behind the poll onto the upper neck, and holds multiple headstalls together when a cavesson or second bit is added, and holds the throatlatch in place on designs where it is a separate strap. In certain sports, such as dressage and Saddle seat, decorative browbands are sometimes fashionable.
Noseband: the noseband encircles the nose of the horse. It is often used to keep the animal's mouth closed, or to attach other pieces or equipment, such as martingales. See also Noseband.

Cavesson is a specific type of noseband used on English bridles wherein the noseband is attached to its own headstall, held onto the rest of the bridle by the browband. Because it has a separate headstall (also called sliphead), a cavesson can be adjusted with greater precision; a noseband that is simply attached to the same cheekpieces that hold the bit cannot be raised or lowered. In Saddle seat riding, the cavesson is often brightly colored and matches the browband. Variations on the standard English-style bridle are often named for their style of noseband. For use in polo, a gag bridle usually has a noseband plus a cavesson.

Frentera, a strap running from the browband to the noseband, primarily seen on bridles of certain South American designs.

Reins: The reins of a bridle attach to the bit, below the attachment for the cheekpieces. The reins are the rider's link to the horse, and are seen on every bridle. Reins are often laced, braided, have stops, or are made of rubber or some other tacky material to provide extra grip.

Bit: The bit goes into the horse's mouth, resting on the sensitive interdental space between the horse's teeth known as the "bars"
On a double bridle, where the horse carries two bits (a curb and small snaffle, often called a "bit and bradoon"), a second, smaller headstall, known as a 'bradoon hanger' or ‘slip head’is used to attach the bradoon.
A second set of reins is attached to the bradoon, and hence the rider carries four reins.
The bridle, depending on style, may also contain some of the following elements:

Curb strap or curb chain, used primarily on bridles with a curb bit, a small strap or chain, usually flat, that runs from one side of the bit to the other, and puts pressure on the chin groove when curb reins are tightened.

Lip strap: a small strap used on a few curb bit designs, attaches between the bit shanks of a curb bit at the halfway point, used to keep the curb chain properly positioned and may prevent the horse from grabbing at the shanks with its lips.

bit hobble: basically, a curb strap used on the snaffle bit rings of a western bridle. Provides no leverage, but because open-faced bridles have no cavesson to prevent the horse from gaping its mouth open, it prevents the bit rings from being pulled through the mouth if strong pressure is applied.

shank hobble: A strap, bar or chain that connects the shanks of a curb bit at the bottom of the bit. Serves to stabilize the bit, prevent a lasso or other object from being caught on the shanks.

Winkers or Blinkers, also called "blinders," are partial eye blocks used primarily on driving horses and some race horses that prevent the animal from seeing what is behind it.

Overcheck, also called a bearing rein or "check rein," is a specialty rein that runs from a snaffle bit, past the crownpiece, along the crest of the neck, and attaches to the front of a harness on a driving horse. It prevents the horse from dropping its head too low. Overchecks are also sometimes used on riding horses, especially ponies, to keep them from grazing while being ridden by a small child who may lack the physical strength or skill to raise the animal's head up.