Water heaters are appliances used to heat water for various purposes, such as domestic use, bathing, cooking, and space heating. They are essential for providing hot water in homes, businesses, and other buildings. Water heaters consist of a tank that stores and heats a specific amount of water, typically ranging from 20 to 80 gallons. The water is continuously heated and maintained at a set temperature, ready for use whenever needed. Some common brands include Ariston, Choice, Ideal Standard.