Jim,

Look to the picture, my most simple explanation.

Daniel Bernoulli (Dutchman), higher speed of air lower pressure.

The air underneath the wing is forced through a narrow space, so pressure will be lower near the TE of wing and stab.

Above the wing the air is divided over a greater space, so higher pressure.

The pressure difference will give you downwash (blue arrows), (Newton) is equivalent for lift.

The dihedral is important to get a stabile flight, this will give a better pressure distribution and less loses near the wingtip, third picture.

Cees