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Airflow separation, or the creation of turbulence on the upper surface of the airfoil, is another symptom of excessive angle of attack. Basically the wing is operating at such a high AOA that air cannot smoothly flow around the leading edge and turbulence is the result. Imagine a piece of paper held at 90 degrees to the wind and you get the idea. You can use various tricks to change the contour of the wing (leading edge devices like slats, fixed or movable) or a slot, but with even with that stuff sticking out the wing still has a critical AOA that it will stall at regardless of airspeed.

"Laminar flow" describes an airfoil that has been designed to promote laminar flow over its surfaces, reducing turbulence and lowering drag. We didn't really understand it until the 1930's but it was later used to good effect in the P-51 Mustang. Unless the wing has a very smooth surface, like today's composite wings or very well made riveted aluminum ones, surface imperfections will break up laminar flow, resulting in drag.

We all know that there are symmetrical airfoils out there that defy the old "bernoulli" theorem as to why the wing produces lift. There's a raging debate as to whether lift is caused by the pressure imbalance between top and bottom surfaces, or whether it's a newtonian reaction caused by the wind striking the lower surface of the airfoil and being redirected downward, causing an equal and opposite reaction upward in the form of lift.

And you have probably seen the strakes on an F-18, that run from the wing leading edge up toward the cockpit: these are also useful for producing lift.