WW1 took place earlier than WW2.
WW1 was central powers vs Allies, WW2 was Axis vs Allies.
WW1 was caused by Militarism, imperialism, nationalism, and the assassination of archduke Ferdinand. WW2 was caused by German aggression.
WW1 dealt with a lot of trench warfare, WW2 had a lot of submarine and civilian casualties.
WW1 brought the League of Nations, WW2 brought the United Nations.
WW1 came to a conclusion by Germany surrendering. WW2 came to an end with the dropping of the atomic bombs.
WW1 turining point was american entering the war, WW2 turning point is D-day landings and Battle of Stalingrad.
WW1 saw less combat on the western front, WW2 saw heavy combat on all fronts.
WW1 was started by Austria-Hungary, WW2 was started by Germany.
I hope this helps! :)
