Millions upon millions of barrels of oil are used around the world every day. It is one of the most significant sources of energy in use today, though it can be a controversial one. This informative book covers the important processes of this fossil fuel, from its origins and formation to its extraction and refining, aided by full-color photographs that closely correlate with the text. Readers consider the controversies surrounding oil's use as well as learn of its surprising applications in history.