Please describe what combat was like in World War I

Context: World War I was fought on many fronts around the world from the battlefields of Europe to the far-flung colonies in the Pacific and Africa. While it is most famous for the trench warfare stalemate that existed on Europe's Western Front, in other theatres of combat the fighting was mobile and often involved set-piece battles and cavalry charges. The Eastern Front often took thousands of casualties a day during the major offensive pushes, but it was the West that saw the most concentrated slaughter. It was in the west that the newly industrialized world powers could focus their end products on the military–industrial complex. The deadliest day of the war was during the opening days of the conflict. The Imperial German war council had initiated the Schlieffen Plan which involved multiple armies flooding through the borders of Belgium and France. On August 22, 1914, during the Battle of the Frontiers, five separate French armies engaged the German invaders independently of each other. Across all those battlefields, on that single day, 27,000 French soldiers lost their lives protecting their country.

Answer: World War 1 was fought in Europe, the Pacific, and Africa. It involved cavalry, trench warfare, and mechanized combat. While World War I is known primarily for trench warfare, it also involved mobile combat and the movement of tens of thousands of men, machines, and animals. There were numerous, bloody days and battles in World War I, but the most deadly took place during the opening days of the conflict, at the Battle of Frontiers, where 27,000 French soldiers were killed in a single day.