A swimming pool is a large hole that has been made and filled with water so people can swim in it. Swimming pools may be indoor or outdoor. They can also be shaped to be rectangular, oval, or kidney-shaped. People can swim in pools for recreational purposes, such as relaxing and tanning, or for exercise and fitness. They can also be used for events and competitions, such as swimming races, diving and synchronized swimming. In addition, pools are often used for specialist tasks, such as training for aircraft and submarine crews to escape from ditching in deep water or as a form of exercise therapy for people with chronic illnesses.
Lap pools, or fitness/training pools, are a type of swimming pool that has been designed so that swimmers can do laps for health and fitness. These pools are usually long and narrow. They can vary in width from one to three swimming lanes.
The size and shape of a swimming pool can be influenced by the available space, the intended use, and the budget of the pool owner. For example, a smaller pool can be less expensive to build, but it may not be suitable for all swimmers.
The most popular use of a swimming pool is recreational at-home leisure. In fact, most pools in the United States are used for this purpose. The most common residential pools are above-ground pools. Pool builders will typically construct a deck or other weight-bearing structure around the above ground pool to provide reinforcement and extra strength once it is full of water and people.