fossil fuel is a general term for buried combustible geologic deposits of organic materials, formed from decayed plants and animals that have been converted to crude oil, coal, natural gas, or heavy oils by exposure to heat and pressure in the earth's crust over hundreds of millions of years.
Fossil fuels are buried geologic deposits of organic materials. They are made of decaying plants and animals that have been turned into to natural oil. A few examples of fossil fuels are coal and oil.
