Offensive linemen are players on the football team responsible for protecting the quarterback and creating openings for running backs. They line up at the front of the offense and work together to block defenders, ensuring that plays can develop effectively. Their roles include tackling, guarding, and center positions, each with specific responsibilities. Defensive linemen, on the other hand, are tasked with stopping the opposing team's offense. They line up across from the offensive line and aim to tackle the quarterback or disrupt running plays. Their positions include defensive tackles and defensive ends, and they play a crucial role in defending against both the pass and the run.