Gas water heaters are appliances that use natural gas or propane to heat water for residential or commercial use. They typically consist of a tank that stores hot water and a burner located at the bottom, which heats the water as it flows through the tank. These heaters are known for their efficiency and ability to provide a continuous supply of hot water. When choosing a gas water heater, factors such as tank size, energy efficiency, and installation requirements should be considered. Regular maintenance, including checking the thermocouple and venting system, is essential to ensure safe and efficient operation.