The civilized world depends on fuel much as the human body depends on food for life and strength.
Fuels provide people with most of their electric power and make modern transportation possible.
Without fuels there would be no industrialized world as it exists today. Most common fuels are similar to food in many respects. They contain carbon compounds and are known as fossil fuels because they are found in the earth as the end product of organic matter left behind by plants and animals and buried millions of years ago. Such fuels are burned in air, combining with its oxygen in a chemical reaction that produces heat. This heat can then be converted into mechanical or electrical energy.