A cornerback is a position in American football primarily responsible for defending against the opposing team's wide receivers. They play on the outside of the defensive backfield and aim to prevent passes from being completed. Cornerbacks use their speed, agility, and skills to cover receivers, intercept passes, and tackle players who catch the ball. In addition to pass coverage, cornerbacks also support the run defense by tackling running backs and blocking plays. They often face challenges from skilled receivers, making their role crucial in a team's defensive strategy. Successful cornerbacks, like Deion Sanders or Darrelle Revis, are known for their ability to read the game and react quickly.