Go to
the definition that best fits your i.q. range.
under 60: a robot
60-80: a machine that makes your lawn crap on itself
80 and higher: a propelled machine that you guide across your lawn. it punctures holes about have inch around, and 2 inches deep,
in the ground. this allows nutrience to seep deeper into your soil, loosens
the dirt, and helps you grow more grass if you are reseeding your lawn