In a chemical sense, no difference, but fire is complicated. Check out Wikipedia articles on Redox, Radicals, Combustion, etc. Fuel cells are cool because they

In a chemical sense, no difference, but fire is complicated. Check out Wikipedia articles on Redox, Radicals, Combustion, etc. Fuel cells are cool because they grab electricity straight from the freed electrons as the fuel is oxidized. More efficient than using the heat to make steam to power a turbine to spin electromagnets, your typical power plant.