It means essentially the same thing as the current 'in-vogue' phrase, "It is, what it is." It means the law is not negotiable. It may not seem just in some cases but it is, above all else, the law.
<P> <P>Laws of conservation is a law and not a theory because it states that a particular measurable property of an isolated physical system does not change as the system evolves....
A law is something that is proved and explains the mechanism of a particular event. Theory is a tentative explanation of a particular event but does not have enough facts to prove it experimentally....