An internal combustion engine is any engine that burns fuel inside the engine - cars, motorbikes, and many types of generator all make use of the internal combustion engine.
The combustion of fuel in a confined space produces gases that are then directly put to work by the engine. The jet engine utilises the principle in the form of the gas turbine.
The principle of the internal combustion engine was technically established by the advent of fireworks in the Chinese Song dynasty, but it was in 1826 that the American Samuel Morey received a patent for his reciprocating internal combustion engine. Christian Huygens, the Dutch physicist, had experimented in the late 17th Century, though it is actually from Gottlieb Daimler's four-stroke, two-cylinder engine of 1889 that most modern car engines are descended.