MEFO is like pretend money that was used by the German government during a time called World War Two. Imagine you and your friends playing a game where you use special coins or marbles to buy things from each other. That's kind of what it was like for Germany, but instead of marbles, they used paper IOUs called MEFO bills.
The German government needed lots of money to pay for the war, but they couldn't just print more paper money like they normally would. That's because they had already printed so much that the money didn't have much value anymore. So they came up with a plan to create MEFO bills, which they would use to buy things they needed, like tanks and weapons.
Here's how it worked: First, the government would make a MEFO bill and promise to pay whoever accepted it back in the future. They would use these MEFO bills to pay companies for the things they needed. The companies could then use these same MEFO bills to pay their own workers, and the cycle would continue.
This worked well for a while, but eventually, people started to realize that the MEFO bills weren't backed up by real money or valuable resources. As a result, people lost faith in the German economy and the value of their currency decreased rapidly.
In the end, MEFO bills were just a temporary solution to a big problem. While they helped the German government pay for important things during the war, they also caused inflation and made life harder for everyday people.