Traditional jetted tubs are much more common than the more recently introduced airpool style of tubs, and they also have very different features than the airpool type. They feature pressurized jets similar to the ones you find in hot tubs and spas, which are positioned to direct vigorous streams of warm water to comfort areas of the body, such as the lower or upper back, shoulders, or legs, providing a vigorous or comforting massage.
Airpool tubs offer a less vigorous, more generalized massage than jetted ones which is an advantage for those users who may be sensitive to the more rigorous jetted type of tub, or prefer more of an all over soothing experience to the more focused massage provided by a standard jetted tub. Airpool tubs feature several small holes in the bottom of the tub which let in air, offering a soothing, effervescent soak as soothing as lying in a bath of warm champagne bubbles.
Jetted tubs use water from the tub in the jets, incorporating pumps to keep water flowing through and conditions sanitary, whereas airpool tubs simply release air bubbles, slightly pressurized, from the bottom of the tub. This means that there are different considerations when it comes to cleaning the two different types of tubs too; The jetted type are both significantly more expensive to purchase as well as more maintenance intensive than the airpool family of tubs. In return, the jetted tubs offer a deeper level of massage, reaching deeper into the muscle tissue than the bubble types which are focused mainly on providing stimulation to the skin.