1. Purchase: The part of the bit above the mouthpiece. With a short purchase, the bit will act quicker in a horse's mouth when the rider pulls on the reins. With a long purchase, the bit is slower to react.

2. Shank: The part of the bit below the mouthpiece that gives the rider leverage on the mouthpiece. The shorter the shank, the less control - the larger the shank, the more control.

3. Cheeks: Sides of the bit - includes both purchase and shank

4. Mouthpiece: The part of the bit that goes in the horse's mouth
Types of Mouthpieces:
A. Snaffle: Broken in the middle and one of the most common mouthpieces.
B. Three-piece snaffle: Broken in two places to work on different portions of the bars than a regular snaffle.
C. Double-twisted wire snaffle: Made up of two small snaffles that are broken off-center from each other.
D. Chain mouthpiece: Works on the corners of the mouth, rather than the bars like a snaffle.
E. Solid mouthpiece: Any mouthpiece that is not broken
i. Bars - Rest on the horse's bars (gums behind teeth)
ii. Port - Rests on the tongue
There are high, medium and low port bits. The closer the bars are together, the more severe. The wider apart, the less severe.
iii. Mullen Relief - A forward curve to the mouthpiece gives even pressure across the mouth. This causes a smoother reaction from the horse.
F. Swivel mouthpiece: The mouthpiece swivels on the shank.
i. Allows independent shank action
ii. Gives the mouthpiece a different action than a solid constructed bit

5. Curb bit: Rotation in mouth, down on mouth, up on curb chain, and pressure on poll.

6. Curb chain pressure: Varies from one bit to another.
Sets timing of the bit.
Loose Curb Chain = slower timing
Tight Curb Chain = faster timing

7. Metals used in mouthpieces
A. Copper: Causes a horse's mouth to salivate which allows the mouth to stay soft and usable to the rider.
B. Sweet iron: It is intended to rust and actually has a sweet taste to it as rusting occurs.
C. Stainless Steel: Gives a clean, neat look to any mouthpiece.

8. The "feel of the bit": Not only what the horse feels when the rider puts pressure on the reins, but also what the rider feels. For example: suppleness or stiffness.

9. Timing: The amount of time required from the point when the reins are pulled until the bit has done as much as it can do.