Final answer:
World War I was the first global conflict in which entire populations worked against one another in campaigns of mass mobilization, technological warfare, and widespread casualties. It was the first industrialized war, and it had a major impact on the world.
Step-by-step explanation:
World War I was the first global conflict in which entire populations worked against one another in campaigns of mass mobilization, technological warfare, and widespread casualties. Lasting from 1914-1918, it was the first industrialized war and involved nations from nearly every continent. The war had a major economic, political, and artistic impact on the world, and millions of soldiers and civilians lost their lives.