I probably have no idea what i am talking about, but here is my question none the less.

I have heard that we have seen the "fringes" of the universe. Now, I have always thought of the universe as being everything that can possibly exist. All that is, is the universe. It makes sense to me that the universe is infinite in everyway, but these "fringes" throw me off. If there are fringes of the universe, doesn't that imply that "something" else lies on the other side of these fringes. If that is so, wouldn't whatever lies on the other side still be part of the universe? I feel like space has to be infinite becuase there is no "center" of the universe, so it must just go on forever.

Now, i feel like i may not be grasping the idea of space. I always hear space compared to a 2d surface (like the surface of a balloon), and i am not sure what that means exactly, because we are obviously in a 3d world. What am i missing?

thank you
reenpeery