Federalism: This is a system of government where power is divided between a central authority and constituent political units, like states. In this case, supremacy clause helps to maintain balance by ensuring that federal laws have ultimate authority.
Constitutional Law: This refers to rights carved out in the federal and state constitifutions. The majority of this body of law has developed from state and federal supreme court rulings which interpret their respective constitutions and ensure that they are aligned with the Supremacy Clause.
Preemption: This legal doctrine holds that if a conflict occurs between federal and state law, the federal law must be applied. It's essentially another way to describe what happens because of the Supremacy Clause.