Hot tubs and spas are pools filled with hot water, used for relaxation or hydrotherapy, and are common in homes, hotels, and health clubs. Special swimming pools are also used for diving, specialized water sports, physical therapy as well as for the training of lifeguards and astronauts.
Many health clubs, fitness centers and private clubs, such as the YMCA, have pools used mostly for exercise or recreation. Many towns and cities provide public pools. Many hotels have pools available for their guests to use at their leisure. Educational facilities such as universities typically have pools for physical education classes, recreational activities, leisure or competitive athletics such as swimming teams.