A deep and relatively narrow body of water (as in a river, harbor, or a strait linking two larger bodies) that allows the best passage for vessels; an open conduit either naturally or artificially created which periodically or continuously contains moving water, or which forms a connecting link between two bodies of water. River, creek, run, branch, and tributary are some of the terms used to describe natural channels. Canal and floodway are some of the terms used to describe artificial channels.