World War 2 consists of many wars/ regional conflicts
Most of the action of WW2 was in East Asia, Europe, and islands in the Pacific ocean. Madagascar and the Aleutian islands were also in the war.
The people involved were the Allies- The United Kingdom led by Prime Minister Winston Churchhill and the United States led by President Roosevelt and the axis -Japan led by Hideki and Germany led by Adolf Hitler
WW2 officially began on July seventh, 1937. All warring countries were in by December seventh of 1941, and the war officially ended on May seventh, 1945.
WW2 started because of Axis aggression. The treaty of Versailles failed to maintain peace. Global economic depression allowed the Nazi party to rise, the western allies abandoned the appeasement policy.
A legacy left by WW2 is that the Nazi hunters continued to track down war criminals who were never brought to justice and another legacy that the Japanese government continues to face criticism for its handling of atrocities committed by the war regime.