It has been suggested that the text below be merged into (added to) the Internal combustion engine page. (Discuss)

Combustion is a word that means burning. An engine is a machine that can push or pull (usually push). A combustion engine is a machine that makes small explosions inside a sealed box (cylinder). The explosions push a rod which is attached to a wheel. The pushing makes the wheel spin around. The spinning wheel is attached to other wheels, such as four car wheels, with a belt or a chain. The engine is very strong and can make all the wheels move. Engines need oil to make them slippery or the moving parts would grind together and stick. Parts of a car engine are measured to 0.01 of a millimeter and some engine parts fit together very, very tightly.

Rockets that go into space are combustion engines but they do not have wheels inside. The fire in a rocket combustion engine is so strong that it blows the rocket the same as blowing a piece of paper.