Laws in day to day may refer to a bill that has been passed in your country creating a law. A law within is Science is usually a fact that remains consistent and doesn’t change (like Newtons Laws). Scientific laws of course are tested to see if they remain accurate consistently before becoming law but they aren’t simply voted in/passes like laws in the judicial system.
Plessy V. Ferguson was only a landmark decision in the Supreme Court of the United States issued in 1896. The impact of Plessy v. Ferguson allowed the statement "Separate but equal" also known as segregation to become law in U.S. After this event, Jim Crow laws which were a system of laws meant to discriminate against African Americans, spread across the United States.
