what is vane

A vane is a flat, thin, or curved object often attached to a rotating axis or wheel, which moves when pushed by air or water. It can be a weather vane, a device mounted on a building to show wind direction, or a blade part in machines like windmills or fans that help regulate or indicate fluid flow. Additionally, in bird anatomy, the vane is the flattened surface of a feather formed by branches called barbs, which are further structured for stiffness.