Airspeed is the speed at which an aircraft travels relative to the air mass it is traveling through. This contrasts with groundspeed, which, not surprisingly, is the speed at which the aircraft is traveling relative to the ground.
If the plane is moving through still air then its airspeed equals its groundspeed. If, on the other hand, there is a wind at the altitude the plane is flying at then groundspeed and airspeed will differ.
For example, consider a plane that is flying toward the north at, say, 30 miles per hour. If the wind at that altitude is also blowing at 30 miles per hour from south to north, then the plane’s groundspeed is 30, but it’s airspeed is zero because the plane and the air are traveling in the same direction at the same speed.
In that case, if the pilot, crew and passengers don’t have wills, or if their wills are out of date, they should probably try to find a way to transmit a new will from the plane because planes generally can’t maintain lift when they are flying that slowly. Crashing may be in the plane’s immediate future.