Pocket Veto: This occurs when a president neither signs nor vetoes a bill within ten days while Congress is not in session, resulting in the bill not becoming law.
Override: This term refers to the process by which Congress can pass a bill into law despite a presidential veto, requiring a two-thirds majority vote in both houses of Congress.
Line-item Veto: A line-item veto allows the president to reject specific parts or provisions of a bill while signing the rest into law. However, this power is not granted to the U.S. president.