Basic differences are :
Work Step by Step
1.A law is an observation; a theory is the explanation of that observation. 2.A theory requires experimentation under various conditions. A law has no such requirements. 3.A theory may become obsolete with time. This is not the case with a law. 4.A theory can be replaced by another better theory; however, this never happens with a law. 5.A theory may be strong or weak according to the amount of evidence available. A law is a universally observable fact.