You successfully explain the bank's business model, from collecting depositors' funds, extending loans, to profiting from interest rate differentials and service fees. Concrete examples, such as the simple figure of "8% on loans vs. 3% on deposits," help readers grasp the core concept...

This is a good introduction for lay readers to understand how banks generate profits. With a little more depth on the risk aspects and diversification of revenue streams, your writing would be more balanced and useful.