Fuel

Fuel is a substance that stores chemical or nuclear energy, which can be released to produce heat, power, or light through combustion or other energy conversion processes. Fuels are broadly classified into three types: solid fuels (e.g., coal, biomass), liquid fuels (e.g., gasoline, diesel), and gaseous fuels (e.g., natural gas, hydrogen). They are essential in industries, transportation, and power generation. With growing environmental concerns, renewable and sustainable fuel alternatives, such as biofuels and hydrogen, are gaining prominence.