Combat in the first world war was heavily infantry based. Theoretically, attackers were supposed to leave their trenches and charge through "no man's land" to the enemy's front line, staying low to the ground to avoid gunfire and explosions. If the attackers succeeded, they would overtake and seize the opposing trench, winning the battle. However, in World War I the defenders typically won because of better positioning and cover. Many times, they also had machine guns set up in the trenches, while attackers were forced to drag their equipment from the trenches and into battle with them. Massive infantry charges were many times suicidal in World War I because of the effectiveness of artillery and machine guns, and many battles were standstills for days to even weeks on end. Giant tanks and landships were also a new technological innovation which was first seen in World War I. Tanks were used mostly by the Allies, with the first tank being built in Great Britain and the French ultimately producing the most tanks in the war. While tanks were feared during World War I, they also were poorly used and designed. For example, on the Nivelle Offensive, the French used tanks for the first time. However, most of the tanks were taken out quickly by German artillery. Heavy tanks known as the Saint-Chamond were also poorly designed and many times were unable to cross the German trenches. Naval warfare also occurred in WWI. Dreadnought battleships were the most deadly ship, and submarines were also introduced and commonly used by the Germans. Sonar use was also in development by the end of the war. Aviation, on the other hand, was rarely used during WWI, with the majority of planes being used for scouting.
While infantry was also a large part of World War II, trench warfare rarely occurred in battle. Instead, land warfare was much more mobile, allowing the attackers to have the advantage throughout the war. Tanks, which were much more advanced in terms of design, became the primary focus of many land battles. They were faster and stronger than their World War I counterparts. Although tanks were a large part of the war, there were few tank vs. tank battles between the Axis and the Allies, as the Axis forces relied on artillery, grenades, and anti-tank guns to destroy Allied tanks, rather than fight with their own. Naval and air warfare became much more significant as well, especially in the Pacific. The most important part of naval technology were the aircraft carriers, and submarines were useful as well. For example, for Americans naval warfare was especially important against Japan. When many of Japan's aircraft carriers were destroyed, many highly experienced Japanese pilots and officers were killed. less experienced Japanese pilots had to fight in aerial battles, leading to huge American victories such as the Great Marianas Turkey Shoot, where almost 350 Japanese aircraft were lost. Submarines and their deadly torpedoes were also used to sink ships. Overall, warfare was very different in WWI and WWII due to new technology, which led to advancements in tanks, ships and planes.