The lift generated by a traditional airfoil configuration is in the upward direction. If the geometry of the airfoil is reversed i.e the airfoil is turned upside down, like how you find on a formula 1 car, the high pressure region is now on the top side of the airfoil and the net force will be in the downward direction which is referred to as downforce.
You could look into this Ansys Innovation Course to explore more on downforce. There is also a cool simulation that you can do on downforce for an F1 car!
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