A Defensive Lineman is a player on a football team whose primary role is to stop the opposing team's offense. Positioned at the line of scrimmage, they aim to tackle the ball carrier or pressure the quarterback. Their strength and quickness are crucial for disrupting plays and protecting their teammates. Defensive linemen typically play in various formations, such as a 4-3 or 3-4 defense, which refers to the number of linemen and linebackers on the field. They must be skilled in techniques like shedding blocks and using their hands effectively to navigate through offensive players.