Feathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds They aid in flight, thermal insulation, waterproofing and coloration that helps in communication and protection.
There are two basic types of feather: vaned feathers which cover the exterior of the body, and down feathers which are underneath the vaned feathers. The pennaceous feathers are vaned feathers. Also called contour feathers, pennaceous feathers arise from tracts and cover the whole body. A third rarer type of feathers, filoplumes, is hairlike and grows along the fluffy down feathers. The remiges, or flight feathers of the wing, and rectrices, the flight feathers of the tail are the most important feathers for flight