Other contributors have said "How did airplanes change war in WWII?" is the same question as "How did airplanes change war in World War 2?" If you believe that these are not asking the same thing and should be answered differently, click here
World War II airplanes provided fire to support troops on the ground, ferried paratroopers back and forth across the battlefield, dropped supplies, and destroyed enemy cities, just to name a few...
Better weapons, vehicles, planes, boats (Uboats), Dogfights, many other more but the main on is WW2 was open fighting not in trenches, well they used trenches but not as much as WW1Did World War 2...
As the name "World War" suggests, it involved most of the world. Major areas of combat included Europe, Africa, Asia, with some combat in North and South America.