The larynx, or "voice box," is the cartilaginous structure at the top of the trachea, or "windpipe," which is in your throat. The larynx contains the vocal cords.
The Greek word laryngos means "the upper windpipe." The larynx does all sorts of important things besides housing the vocal cords (which are actually folds, not cords). The larynx is involved in breathing, and it also helps keep food from entering your windpipe when you swallow. All mammals have one — the wolf that howls, the lion that roars, and Tarzan, who makes that — whatever that sound is he makes.