Why does civilazation have laws?

I think civilazations has laws because without laws the world would be maham! Everything in shops will be taken, people would get shot, everyone driving would crash because they would all run red lights. I think hammurabi's laws were meaniful i say that because if someone builder killed someone because the house dell down with the owner in it, and the owner dies; the builder himself gets sentanced to death because it is like the saying " an eye for an eye" what you give you get.