"Okay kiddo, so back in World War II, there was something called 'cash and carry.' This meant that other countries could buy weapons and supplies from the United States, but they had to bring their own ships to pick them up and pay with cash instead of credit.
You know how you have to have money to buy things from the store? Well, it was the same for other countries. They had to have money to buy things from the United States during the war.
But there was a catch. The United States didn't want to get involved in the war too much, so they made it so other countries had to bring their own boats to pick up the weapons and supplies. This was called 'carry.'
So basically, other countries could buy things they needed to fight in the war from the United States, but they had to pay with cash and bring their own boats to carry the stuff back home."