A bitless bridle is a general term describing a wide range of headgear for horses or other animals that directs the animal without using a bit. Direction control may also be via a noseband or cavesson
A cross-under bitless bridle
A classic bosal-style hackamore
An English-style Jumping Cavesson
The bit shank is the side piece or cheekpiece of a curb bit, part of the bridle, used when riding on horses. The bit shank allows leverage to be added to the pressure of the rider's hands on the bit.
A classic "Santa Barbara" style bit shank, designed for western riding and decorated with silver for use at horse shows
This photo shows all possible elements of a western shanked bit, including loose cheek, "slobber bar," mouthpiece, curb rein ring, snaffle rein slot, and curb chain that applies leverage to the chin groove.
A shank on a spade bit in a horse's mouth.
This photo shows all the elements of an English shanked bit, including cheek, rings for both snaffle and curb reins, a small attachment point for a lip strap, curb hooks for a curb chain, mouthpiece and curb chain