Oh, I love this so basically a theory is something that answer why or how something happens and is something that has been widely accepted by other scientist. For example, The Theory of Relativity many of the things stated are hard to be proven, differ in scientist opinion, and still has sone doubt in it.
However through many observations, overall
they agree so and so does happen, but some concepts are still very broad.
Now a law is true and reliable, there is no doubt. For example, the Law of inertia, which is basically resistance in change of velocity and this is proven. A elephant is harder to push than a cat, every time it doesn't change.
Now an overview:
Theories: - Why something happens
-Explanation & Evidence
Laws: What WILL happen
-All Possible Outcomes & Evidence