The internal combustion engine uses a compression and expansion of the gas to produce a torque or force. The "cold" gas is compressed, and the "hot" gas is expanded. For compressed cold gas, less mechanical energy is consumed than is obtained from the expansion. Because of this, the energy obtained from the expansion is used to compress the gas and to drive any machine. The hot gas is obtained as a result of fuel combustion, hence the name comes from the internal combustion engine.
However, to set in motion the whole vehicle, the engine alone is not enough, you also need the engine equipment, which will provide the right amount of fuel to the engine, reduce torque, and will also set in motion all the elements of the drive unit. In cars, the most common use is a piston engine, in which the energy of an explosive combustion fuel is converted into mechanical energy.