Trench Warfare: A type of combat where opposing forces dig deep trenches to protect themselves from enemy fire. Soldiers would live and fight from these trenches, resulting in static and deadly battles.
Chemical Warfare: The use of toxic gases or chemicals as weapons during warfare. This brutal tactic caused great suffering and casualties among soldiers.
Machine Guns: Rapid-firing firearms capable of firing many rounds per minute. Machine guns revolutionized warfare by increasing firepower but also resulted in higher casualty rates due to their devastating impact on the battlefield.