A spa is a large tub or small pool full of heated water and have powerfull jets and it’s used for hydrotherapy, relaxation, pleasure or for massage purposes. The spa is also known as a hot tub or a Jacuzzi and it comes now a days in different shapes and sizes.
In contrast to a typical bathtub, a hot tub is designed to be used by more than one person at a time, the water in a hot tub is not changed with each use but is kept sanitary using methods similar to those used for swimming pool sanitation.
The spa or Jacuzzi also have a filtration system similar to those used for swimming pools. Heating can be done by either heat element, heat pump or with solar panels.