World War I ( also known as the First World War and the Great War ) was a global military conflict that embroiled most of the world 's great powers , assembled in two opposing alliances : the Entente and the Central Powers .
World War I ( also known as the First World War and the Great War ) was a global military conflict that involved most of the world 's great powers . The war was assembled in two opposing groups : the Entente and the Central Powers .