Fractional Reserve Banking refers to a banking system which requires the commercial banks to keep only a portion of the money deposited with them as reserves. The bank pays interest on all deposits made by its customers and uses the deposited money to make new loans.
This design does a good job of showing the audience the scale of the amount of money involved. Each $100 stack of bills is carefully used to visualize the amount of money being used in the explanation, and it makes a bigger impact by making it visual.
The designer here did a really good job of telling a simple, focused story in the the infographic that is quick and easy for readers to understand.