Commonly referred to parts of a fish hook are its point-the sharp end that penetrates the fish's mouth or flesh; the barb-the projection extending backwards from the point that secures the fish from unhooking, the eye-the end of the hook that is connected to the fishing line or lure, the bend and shank--that portion of the hook that connects the point and the eye, and the gap-the distance between the shank and the point. In many cases, hooks are described by using these various parts of the hook. Example: Wide gap, 2X Long Shank, Hollow Point, Turned Down Ring Eye Bait hook.
Contemporary hooks are manufactured from either high-carbon steel, steel alloyed with Vanadium or stainless steel depending on application. Most quality fish hooks are covered with some form of corrosion resistant surface coating. Corrosion resistance is not only required when hooks are used, especially in saltwater, but while they are stored. Additionally, coatings are applied to color and/or provide ashtetic value to the hook. A minimum, hooks designed for freshwater use are coated with a clear lacquer, but you can find hooks coated in gold, nickel, teflon, tin and different colors. Mustad for example produces hooks in six colors including black.
