A tank water heater is a common appliance used to heat and store water for residential and commercial use. It consists of a large insulated tank that holds a specific volume of water, typically ranging from 20 to 80 gallons. The heater warms the water using either electricity or gas, ensuring that hot water is readily available for activities like bathing, cooking, and cleaning. These heaters operate by continuously maintaining the water temperature, which means they can provide a steady supply of hot water. However, they may run out of hot water during heavy usage, requiring time to refill and reheat the tank. Regular maintenance is essential to ensure efficiency and longevity.