Supremacy refers to the principle that federal law takes precedence over state law when there is a conflict between the two. This foundational concept ensures that the Constitution and federal laws are the ultimate authority in the United States, establishing a clear hierarchy in the relationship between state and federal governments. The supremacy clause, found in Article VI of the Constitution, reinforces this idea by stating that the Constitution, along with federal laws made pursuant to it, shall be the supreme law of the land.