A water heater is a device that heats water for various domestic and commercial uses, such as bathing, cooking, and cleaning. They come in different types, including tankless, storage, and solar water heaters, each with its own method of heating and storage. Most water heaters operate by using electricity, natural gas, or propane to heat the water. The heated water is then stored in a tank or delivered on demand, depending on the type. Regular maintenance is essential to ensure efficiency and longevity, helping to prevent issues like sediment buildup and leaks.