Full-backs are defensive players in soccer who primarily operate on the left and right flanks of the field. Their main responsibilities include blocking opposing wingers, preventing crosses, and supporting the central defenders. Full-backs are crucial for maintaining team shape and providing defensive stability. In addition to their defensive duties, full-backs often contribute to the attack by overlapping with wingers and delivering crosses into the opponent's penalty area. This dual role makes them versatile players, as they need to possess both defensive skills and the ability to support offensive plays effectively.