On its website, Lowe's categorizes water heaters into five major types: electric, gas, hybrid, point-of-use and tankless, as of 2015. Within each category, the retailer carries dozens of brands and types and hundreds of water heater products.
Electric water heaters rely on electricity, usually from the power grid, to heat water. Gas water heaters use natural gas or propane to heat water, and hybrid units rely on both electric and gas for optimum efficiency and reliability. A tankless water heater heats water as it's needed, saving energy by not keeping a well of hot water in the tank. A point-of-use water heater is installed at the sink or reservoir for fast hot water at a single location.