A "four-stroke" engine is a type of internal combustion engine that completes four distinct phases during each cycle: intake, compression, power, and exhaust. This process allows the engine to convert fuel into energy efficiently. The four strokes are achieved through the movement of the piston within the cylinder, which is driven by the combustion of fuel and air. In the intake stroke, the engine draws in a mixture of fuel and air. Next, during the compression stroke, the piston compresses this mixture. The power stroke follows, where the compressed mixture ignites, pushing the piston down. Finally, in the exhaust stroke, the engine expels the spent gases, readying it for the next cycle.