A more thorough explanation:

The United States Court of Appeals is a type of federal court that has the power to hear cases in one of the 13 judicial circuits of the United States. These circuits include the First Circuit through the Eleventh Circuit, as well as the District of Columbia Circuit and the Federal Circuit.

For example, if a case is appealed from a district court in the First Circuit, it would be heard by the United States Court of Appeals for the First Circuit. Similarly, if a case is appealed from a district court in the District of Columbia, it would be heard by the United States Court of Appeals for the District of Columbia Circuit.

The United States Court of Appeals is sometimes also referred to as the circuit court.

Overall, the United States Court of Appeals plays an important role in the federal court system by providing a way for parties to appeal decisions made by lower courts and ensuring that the law is applied consistently across the country.