Hey there! I'm happy to help!The president is the person who nominates new federal judges. Congress simply approves it. For example, President Trump nominated Brett Kavanaugh and Neil Gorsuch to the Supreme Court.The Supreme Court declares laws unconstitutional. Their main job is to interpret the constitution. One of their rulings was that segregation in schools is unconstitutional in the Brown v. Board of Education case.The President is also the person who grants pardons to federal offenders. For example, President Trump recently pardoned Susan B. Anthony, a women's rights activist that was never pardoned for voting when it was illegal for women to vote. Congress ratifies treaties. This is located in Article II Section 2 of the Constitution. The President creates them and they approve them. Have a wonderful day! :D