A cavesson noseband, or plain noseband, is used with horses to accomplish a variety of goals, including discouraging movements that allow a horse avoid a bit, such as crossing its jaw. Cavesson nosebands also help keep the horse's mouth closed and quiet.
A noseband helps to hold a bridle in place as well. A cavesson noseband goes around the horse's nose two finger's width under the cheekbone. It should be adjusted to be fairly snug. It is a good noseband option for a horse that accepts bits well. Other types of nosebands for horses include crank, flash, drop and figure-eight nosebands.