How could the wehrmacht and the U.S. supply their massive armies?

What I really want to know is how they supplied their tank divisions with the enormous amounts of fuel needed to go across the continents they were fighting on. The Germans got all the way to North Africa.

Also, what about the Luftwaffe for when they did Blitzkrieg attacks in remote battlefields. Where and how did they supply all the fuel?

Are we talking literally massive network of fuel trucks?