* For a car? Gasoline (petrol) or diesel are the most common choices, although electricity is rapidly gaining ground.
* For a power plant? Natural gas, coal, nuclear, or renewables (solar, wind, hydro) are all major choices, depending on location, regulations, and cost.
* For a rocket? Solid rocket fuel, liquid hydrogen, kerosene, or other specialized propellants.
* For heating a home? Natural gas, propane, heating oil, or electricity.
To answer your question accurately, I need more information about *what* needs fueling.
