War
War is a state of armed conflict between states or societies. It is generally characterized by extreme aggression, destruction, and mortality, using regular or irregular military forces. Warfare refers to the common activities and characteristics of types of war, or of wars in general. Total war is warfare that is not restricted to purely legitimate military targets, and can result in massive civilian or other non-combatant suffering and casualties.
World
The world is the planet Earth and all life upon it, including human civilization. In a philosophical context, the "world" is the whole of the physical Universe, or an ontological world (the "world" of an individual). In a theological context, the world is the material or the profane sphere, as opposed to the celestial, spiritual, transcendent or sacred spheres. "End of the world" scenarios refer to the end of human history, often in religious contexts.