World War I was fought completely different than any war prior to it. Wars before the First World War were fought on horses in a gentlemen's war. However, by the turn of the century, new technology had been invented which changed the ways of war drastically.
By no means could World War I be considered a gentlemen's war. In previous wars, enemies charged at you in open fields, and you would stay in place while the enemy was shooting directly at you. However, in this war, new weapons were used because of the new technology. These included machine guns that could fire extremely fast and bayonets. Also, tanks were invented which protected the crews and could break through barbed wire that was in front of the trenches. Planes, which were only invented a decade ago, were first used for spying on the enemy. Later, machine guns were attached to the planes. Canons could fire much farther, and created a much greater amount of damage. As well, guns containing metal balls and fragments were constantly fired. Germany's "Big Bertha" artillery could hit targets up to 120 km high and 25 km up, creating giant craters. As well, soldiers fired guns off of railcars. Even though using gas in wars was banned by an act, the Germans still used it against the Allies. This gas was incredibly poisoness. This included chlorine gas. Some types of various gases would make you drown in your on blood, while others would blind you. Mustard gas gouged extremely painful blisters on your skin and melted your lungs. So, soldiers were equipped with anti-gas respirators. This technology was a definite advancement, but the only problem was, the commanders did not know how to make plans with these new weapons and ways of fighting.
The war at sea was different in World War I as well. The Germans built new ships called U-Boats which could destroy any British ship. The U-Boats did this by firing torpedoes which were fast, under water bombs. So, at first, Britain could not