Leave it to some scientifico to point out there is no part identified as a "click". That's because the click is a sound that is made by the interaction of the spring, pawl, and gear; but only when the reel is doing what it is designed to do, revolve. So rather than say "Clicking from the spring, pawl, and gear all working together as the spool revolves." which anyone will tell you is a fucking mouthful and a half, some juvenile unintentionally made it easier on us all by shortening it to click and pawl. Can I get an Amen!
Same could be said for right hand wind...click and pawl reels.