what are control arms and what do they do?

 

well if your takin about stock control arms then there part of you suspension they connect your chasis to your hub which holds your wheels and allows them to move up and down...if your talkin about after market light weight control arms like these babies... ...then they make you suspension lighter which takes off *unsprung* weight which allows your suspension to move up and down faster which allows for your tire to stay on the road more which gives you better handling!! and they look really hot!!