What is the role of of the federal government in dealing with state laws?

There is a Supremacy Clause that states that a state judge must follow the federal law when there is a conflict between federal law and state law in a situation.

There is a following question that is the state law going to prevail over federal law of if the person can get more out of the state law. The answer is no because when the state and federal laws disagree, a concept called supremacy clause comes to light. According to supremacy clause, federal governments is the winner in these conflicting situations. It shows that federal law prevails over the state law.