And within each of these there are varying degrees of pressure. A good example is your posture, from standing still to jumping up and down like a gymnast.
Pressure is used to get a horse to do something, desensitization, or as an excercise.
But mainly we use pressure to work with the horse to follow a feel. There is a difference between desensitizing a horse by using pressure and teaching a horse lightness through feel by using the concepts discussed below. This might sound like a contradiction of everything that you have been taught. Your day to day handling of your horse should minimize pressure, but you must occasionally experiment with different pressure situations for training or to desensitize your horse. Many people believe that you should never stimulate a horse to the point where they have to be uncomfortable with a situation.