The study of the motion of gasses (in this case air), how this motion effects the movement of an object, and how the shape of the object affects airflow.
The portion of a spoiler or wing that's typically angled to catch passing air. Factory-style spoiler decks usually run parallel to the trunk lid, eliminating drag and downforce. Certain wings have adjustable decks for tuning the effect on your vehicle.
The effect of air contacting the car body's sloped surfaces. Downforce is created by the air dam, hood, windshield, roof, spoiler(s) and wing(s) of the car. More downforce increases drag and slows the car, but raises tire friction and temperature, making the car "stick" to the road. Less downforce raises the top speed by reducing drag, but simultaneously increases loose handling.
Spoilers and wings (mostly wings) contribute to downforce by catching passing air. This force hits the angled deck and rises while pushing down on the car. This downward force stabilizes the vehicle tremendously.
Drag is the word for air resistance that slows down your vehicle while driving. The effect is more pronounced at higher speeds. Drag is reduced by aerodynamic shaping such as curved edges that reduce the air caught by your vehicle.
A flexible ring or integrated part typically made of rubber that's used to make a seal fluid-tight. Gaskets are positioned between your spoiler and the trunk lid to keep moisture from seeping through the holes drilled when installing the spoiler/wing.