At the top vs. On the top

✅At the top vs. On the top

"On the top" is most often used in a physical sense of one thing literally being above or resting on another. And I'd say that "at the top", is something in the general vicinity of the top of something.

For example, your forehead is at the top of your head, a hat is on top of your head. You could even get away with saying that your eyes are at the top of your head, but you wouldn't say they are "on top" of your head. The only things "on the top" of your head would be your hair and a hat.

Hope that helps a little!

Thank you