In science, a law is a concise statement, verbal or mathematical, that summarizes an observation and states what will happen under certain conditions. It is a universally accepted statement, and must never be wrong. Otherwise, any science based upon it would be proven incorrect.

For example, in case of the phenomenon of combustion, Lavoisier validated his hypothesis through a series of experiments and then stated that the mass of an object remains conserved during combustion. This statement became one of the famous laws of chemistry, the Law of Conservation of Mass, which states that ‘Mass in an isolated system can neither be created nor destroyed’.

A scientific theory, unlike a law, is a unifying model that provides an explanation as to why and how something happens. It requires rigorous experimentation and observations conducted over a long period of time to develop a theory. 

For example, the Law of Conservation of Mass did not explain why the mass remains unchanged after combustion. An explanation for this phenomenon was put forward when John Dalton proposed the Atomic Theory. Dalton’s Theory proposed that matter is composed of small, indivisible particles called atoms. Since these particles are merely rearranged, and not created or destroyed in a chemical reaction like combustion, the total amount of mass remains the same. 

Theories are constantly tested and evolve as new observations are made. For example, Dalton’s Atomic theory was improved after scientists found that atoms are in fact further divisible into neutrons, protons, and electrons. Further revisions came with the discoveries of quarks, bosons, and so on. 

Overall, the scientific method framework leads scientists from questions and observations to laws or theory, facilitated by experimental verification of hypotheses, and any necessary modification.

Ultimately, while a hypothesis provides a limited explanation of a phenomenon, the theory provides an in-depth explanation of the observed phenomenon. A law, on the other hand, simply states the observation.