These are the names of the main parts of a feather.

This shows how the structure of the feathers allows the barbs to cling to each other. If you have ever handled a feather, you know that the barbs stick together. If they are separated, you can usually smooth them back together. The little hooks (cilium) on the ends of the barbules catch on the flaps of the barbs on the next feather. Nature's velcro!