History of World war

A world war is "a war engaged in by all or most of the principal nations of the world".[1] While a variety of global conflicts have been subjectively deemed "world wars", such as the Cold War and the War on Terror, the term is widely and usually accepted only as it is retrospectively applied to two major international conflicts that occurred during the 20th century: World War I (1914–18) and World War II (1939–45).

This app is about history and for research Purpose .