In an internal combustion engine, the gas vapor/air mixture enters the cylinder during the stroke.

Intake

The intake stroke of an internal combustion engine may be considered as the start of the cycle. Here, the air/gas mixture enters the combustion chamber and is then compressed. After the compression, the mixture is ignited to drive the piston upwards and turn the shaft to which the piston is connected, driving the vehicle forward.

Less force and energy was applied