Federal courts hear cases involving the constitutionality of a law, cases involving the laws and treaties of the U.S. ambassadors and public ministers, disputes between two or more states, admiralty law, also known as maritime law, and bankruptcy cases. ... Federal laws are passed by Congress and signed by the President.
trial courts, where cases start;
intermediate (appellate) courts, where most appeals are first heard; and.
courts of last resort (usually called supreme courts), which hear further appeals and have final authority in the cases they hear.