Swimming pools come in all shapes and sizes but from the backyard pool to large commercials swimming pools, they all basically work in the same manner - they all use a combination of filtration and chemical treatment to continually clean a large volume of water.
A typical swimming pool needs seven major components:
The basic idea is to pump water in a continual cycle, from the pool through the filtering and chemical treatment systems and back to the pool again. In this way, the pumping system keeps the water in the pool relatively free of dirt, debris and bacteria. Some pools also include heaters in the mix, in order to keep the water at a certain temperature.