How did the axis powers achieve victories in 1939 and 1940?

 the axis powers achieved victory through the process called Blitzkrieg this is lightening war in German this was a process of Panza tanks plowing through enemy lines with the airforce (Luftwaffe) and the infantry following behind to pick u[ the remains and to take away the enemy prisoners it wasn't until the battle of Stalingrad in 1944, this was the first major defeat of the Nazi's, this is when blitzkrieg was beginning to halt.

No clue what is the answer