Distinguish between vanes, barbs and barbules.

Explanation

Barbs:
The Raches is the solid portion of a quill feather of a pigeon attached to the rachis are small filament or barbs.
Vane: The Rachis with the barbs constitute the vane.
Barbules : Each barb is fringed with an oblique set of processes called barbules which have minute hooklets or barbicels. This helps to hook adjacent barbs together to form a continuous blade for striking the air during flight.