What was the main difference between wwi and wwii

People involved, reasons different people were involved, time period, weapons used... i could go on forever ;)

Well, the main difference is the time period that they were fought in, there were many other ones but this is the main one. Hope this helped!

Britain and its empire stood alone against hitler and mussolini. in june 1941, hitler broke the non-aggression agreement with stalin and germany invaded the soviet union. in december, japan attacked the us and britain. the main lines of world war ii had formed.