Whatcha mean, "show activity?" <-- I dunno what you don't know.
So I will give basics: The Wright Brothers plane did not have flaps. Banking the plane to turn it required actually warping the wings of the Flyer.
Early WWI planes used the warped-wing design such as the Eindecker shown above. It really does fly, as you can see.
Curtiss snuck into the tent holding the Wright Flyer to steal the wing-warp idea. <-- Howzat for really obscure trivia?
The problem with wing-warping was efficiency. And added danger. This was overcome by putting an airspace between the wing and the warp part -- now known as flaps. Note the air gap:
View attachment 291214
What else you wanna know?