It’s combustible, so it’s a fuel itself.
The reason why I said what I did is because of HOW you get Hydrogen. You don't mine it, you don't drill for it, you don't harvest it, you manufacture it either from electrolysis of water or the steam-methane reforming process of Natural Gas.
Thus, Hydrogen is in and of itself not a fuel source, it is an energy storage medium created from another energy source.