Defensive backs are players in American football who primarily defend against the opposing team's passing game. They are positioned in the secondary, which is the area behind the linebackers. Their main responsibilities include covering wide receivers, intercepting passes, and preventing big plays. Defensive backs can be categorized into cornerbacks and safeties, each with specific roles on the field. Cornerbacks typically line up directly across from wide receivers and focus on man-to-man coverage, while safeties provide support and help defend against deep passes. Effective defensive backs possess speed, agility, and strong ball skills, making them crucial for a team's defensive strategy.