Structure

Heard of that something has a structure, like the mechanical system, so the people look for the so called structure; then often heard of another way that something is a kind of structure, like point sets, so the people look for the properties of the structure; while recently realized that structure is an angle to view something, like the one, two or three dimensional geometry space, we look at it based on the points, lines and the relations between them, which is called geometry structure, while we look at the higher dimensional real space from the view of sets, which is a kind of generalized points or line, it’s called topology structure, and we can do that from other views or to say structures, but they may be not so clear as the former set view.