What is the fundamental chemical classification of water when considering its use as a direct power source?

Answer

An incredibly stable compound and the spent byproduct of burning hydrogen

Water molecules are extremely stable, meaning significant energy must be added to break their bonds. It is characterized as the ash or spent residue resulting from the combustion of hydrogen.

What is the fundamental chemical classification of water when considering its use as a direct power source?
Chemistrywaterenergyfuelreaction