Is the airspeed different between above and under the wings?
In case of a subsonic attached flow over the cambered airfoil (or a symmetric one at an angle of attack), the airflow speed is higher over the wing and pressure is lower. It is the other way around on the lower surface. 



Source: virtualskies.arc.nasa.gov

Note that this is just the mechanics of the flow over the wing. This is not an explanation of lift.