what are ball joints and upper arms?

On a front wheel drive like yours. There are two driveshafts that supply power from the transmission to both front wheels. These drive shafts ( or cv joints ) have a u joint that allows for turning while power is delivered to the wheels. These cv joints must pass thru the suspension. The suspension must also turn. These ball joints are basicaly the bearings that allow the suspension to turn. An upper and a lower per side.