Page 44 - Beginner's Guide to Aviation

While the camber is the curvature of the surface of an aerofoil represented by the mean-camber line drawn halfway between the upper surface and lower surface. It is essentially a curved line joining the leading edge and trailing edge of the aerofoil.
The maximum camber of an aerofoil determined by the displacement of the mean-camber line from the Chord line. Its location determines whether the aerofoil is heavily or slightly cambered.
FUN FACT:
A heavily cambered aerofoil produces higher lift while a slightly cambered aircraft produces higher speed.
FORCES ACTING ON AN AEROFOIL
Lift Total reaction
Drag
The total reaction acting on an aerofoil is the net force coming from 2 components namely lift and drag. The force perpendicular to the direction of motion from the aerofoil is called lift and the force parallel is called drag.
Lift is the desirable component which supports an aircraft, pushing it upwards in flight. Whereas drag holds back the aircraft, pushing it backwards and creates resistance to an aircraft during flight. For this reason, great efforts are put in place to reduce drag to a minimum.
37