The traction imparts the driving force to the wheels to put them in motion.

In a lawn mower the drive train "passes" the engine power to the blade - to spin it so that it cuts the grass - and, in the case of a self-propelled lawn mower, also to the drive wheels. Based on the number of driving wheels and where they are positioned, the traction of a self-propelled lawn mower can be front or rear if there are 2 driving wheels, integral if there are 4: just like in cars.