There’s a short answer and a long answer to this question. The short answer is that carpal tunnel syndrome affects the wrist and the nerves that pass through it, and cubital tunnel syndrome affects the elbow, and the nerve that passes along it.
Here’s the longer answer: In the wrist, there an area called the carpal tunnel. This is where the nerves from your arm enter your hand. What can happen with repetitive motions is the area becomes inflamed and irritated, and the tendon (tough, fibrous tissue that helps move your fingers), get thicker and presses on the nerves. With cubital tunnel syndrome, it’s repetitive motions of the arm and elbow that cause trouble, or something else that may press on the nerve, like a cyst or tumor. The ulnar nerve, which passes behind the elbow, where you would call your “funny bone” is pressed on and this affects how your hand feels along the ring (fourth) and little fingers.