Simply put, artillery are large calibre guns used on land, where calibre describes the diameter of the barrel. There were three main types of artillery used during World War One; field guns, howitzers and mortars.
Field guns were a direct line of sight weapon, they were used to break down fortifications and to try and dislodge enemy troops from trench networks. The benefit of field guns in trench warfare was diminished however, because of the stalemate nature of this type of warfare.
Howitzers were developed to be used under cover and against hidden targets. They were the best type of artillery to use against fortifications. Howitzers fired heavy shells on a high trajectory through a short barrel.
The most famous howitzer’s were the German Big Bertha and the Austrian Skoda 30.5. As with most weapons used during World War One, howitzers developed as the war progressed. At the outbreak of war, the British howitzer had a very limited range, but by the end of the war they could fire shells over 18km.
The mortar was also a high-trajectory weapon. The mortar was designed to fire the projectile in a way that would make it land directly on top of the enemy. Because of this it was very well suited to trench warfare. The projectile was dropped into a broad, short barrel and was fired by a pre-loaded explosive charge at an angle greater than 45 degrees.The main advantage of the mortar was that it could be fired directly from the trenches, meaning that the mortar and its operators weren’t exposed to the enemy. The mortar was also lighter and more mobile than the other larger artillery weapons.