Coble surface

Okay kiddo, imagine you have a piece of paper, right?

Now if you put your hand on the paper, your hand covers only a certain area, right? That's called a surface area.

Now think of a cobblestone street. Instead of paper, there are lots of little rocks, or "cobblestones", covering the surface. Each of those cobblestones is like a small surface area.

So when we say "coble surface", we're talking about the whole area that's covered by all those cobblestones put together.

Does that make sense, kiddo?