Gear coupling

Ok kiddo, so a gear coupling is just like a puzzle piece that connects two sticks or tubes together. One stick has teeth on it (kind of like the edge of a saw) and the other stick has matching teeth so they can fit together and spin around. This is really useful for big machines that need to move things around because if they're not connected properly, they won't work right. Gear couplings help keep everything in the machine moving smoothly and safely. Does that make sense, little one?