Defensive Pass Interference occurs in American football when a defensive player illegally contacts an offensive player who is trying to catch a pass. This contact can happen before the ball arrives, preventing the offensive player from making the catch. The rules are designed to ensure fair play and protect the rights of the receiver. When Defensive Pass Interference is called, the offensive team is awarded a penalty that typically results in a significant gain of yardage. The penalty can vary in distance, often resulting in a first down at the spot of the foul, giving the offensive team a better chance to score.