The petroleum or crude oil is heated. Then the vapor goes into a fractionating tower. It takes the crude oil and breaks it into parts or fractions. Well, that's exactly what happens in the fractionating tower. The lightest vapors rise to the top while the heavier vapors stay at the bottom.
Several pans collect the vapor as it turns back into liquid.
And different liquids are formed at different levels of the tower. The lightest vapors produce gasoline. Gasoline is used to power automobiles, lawnmowers, powerboats and motorcycles. The gasoline is piped to another area. There the molecules are changed and we get different kinds of gasolines.