What is the difference between war and major events?

What is the differences between war and major events? What are some similarities?|||I am not sure what you mean by a 'major event', but a 'war' is a declared conflict by at least one of the nations in the conflict. The Japan declared war on the United States...after bombs were fulling on Pearl Harbor. In other conflicts there is not a declaration of war, even when both sides are clearly in conflict with each other. Firing on another nations embassy, ships, aircraft or citizens can be considered 'Acts of war' and the injured party would be justified in international law on declaring war on the other party. Non-state organizations often will commit acts of war, but since they are not nation states, their actions are normally considered criminal actions and are normally treated as such.