Scientific law is based on empirical observation of the real world. Scientific laws are a result of repeated scientific experiments that help us to understand some events of the Universe. Scientific laws hold true forever and are widely accepted with the scientific community.
A scientific law generalizes a body of observations. At the time it is made, no exceptions have been found to a law. Scientific laws explain things, but they do not describe them. One way to tell a law and a theory apart is to ask if the description gives you a means to explain 'why'.
In general, a scientific law is the description of an observed phenomenon. It doesn't explain why the phenomenon exists or what causes it.
