The difference between difference between types of snakes

[Skiploder]

but if they all kill by constriction ( rat snakes, corn snakes, pythons, and boas) is the things that classify them as different their size and the way they look?

This is something that you should really endeavor to learn on your own. The taxonomy of snakes is something that deserves to be researched. There is no easy answer to this question on a forum.