Billions of years ago, tiny singled-celled organisms lived in the ocean. When they died, they sunk to the sea bed. As this cycle continued, the layers produced heat. The pressure caused the organisms to change to a waxy substance called kerosene.
When heated, the kerosene separated into a liquid (crude oil) and a gas (natural gas).
We use the natural gas on stoves.
We use the crude oil as gasoline to power our cars! Isn't that cool?