Aids are pressures and/or a combination of pressures used to communicate with your horse. There are two different types of aids. Natural aids are your leg, weight, and rein aids. Artificial aids being whips, spurs, and your voice.

Natural aids are applied with your body. Leg aids are your driving aids, the "go button" on your horse. Weight aids are what you use to set a steady tempo in the gait your horse is performing, wither it be the walk, trot/jog, or lope/canter. Your rein aids should be used less than fifteen percent of the time. Reins are a last resort when your horse doesn't move from your leg. Reins are used to direct your horse were to go from your leg when they don't understand what you are asking.

Artificial aids are used to enforce natural aids when the horse doesn't respond -- not to punish or abuse your horse. A whip is used when your horse isn't responding to your driving legs. When you ask for the trot and you're kicking and smooching repeatedly and your horse isn't trotting, you use your whip to enforce the kicking (driving). Spurs are used to enforce your leg aids for circling or enlarging circles. When used correctly, the horse should not bleed or have scars. Spurs are meant for rolling down the horse's side, not jabbing. Your voice is excellent artificial aid for lunging or lesson horses. It's simply saying, walk, trot, lope, or whoa.

When applying the pressures it has to be repetitive. For example, if I put my finger on your shoulder you could ignore it, but if I kept poking your shoulder, eventually you would move away from my finger. Same goes for a horse when applying the aids mentioned above, because constant pressures fade away.