Trench warfare
Trench warfare occurred when a revolution in firepower was not matched by similar advances in mobility, resulting in a grueling form of warfare in which the defender held the advantage. On the Western Front in 1914–1918, both sides constructed elaborate trench, underground, and dugout systems opposing each other along a front, protected from assault by barbed wire, mines, camouflaged trapping pits, and other obstacles. The area between opposing trench lines (known as "no man's land") was fully exposed to artillery fire from both sides. Attacks, even if successful, often sustained severe casualties.
Artillery of World War I
The artillery of World War I was used primarily to counter the trench warfare that set in shortly after the conflict commenced, and was an important factor in the war, influencing its tactics, and operations, and being incorporated into strategies that were used by the belligerents to break the stalemate at the front. World War I raised artillery to a new level of importance on the battlefield.