An upside-down aeroplane

An aeroplane's wing pushes it up. An F1 car's wings are the same idea flipped over: they push the car down into the track. Why does that matter? Because tyre grip is roughly proportional to how hard the tyre is pressed into the road. Add aerodynamic load and the same four contact patches can transmit far more cornering and braking force — without adding a gram of weight in the corners where weight hurts.