How does money work in a modern fractional reserve system?

Money works like a big jar of cookies shared by a neighborhood. In a fractional reserve system, banks don't keep all the cookies locked away. They only keep a small handful in the jar, while lending out the rest to friends who promise to pay them back. This means many people can "borrow" the same cookie at different times, making money circulate faster.

Imagine you have 10 chocolate chip cookies. You put 2 in a jar for emergencies (reserve) and lend 8 to your friends. Those friends use those cookies to trade for toys or snacks. Later, they return the cookies, maybe with extra crumbs as a thank-you gift (interest). Because the bank didn't hoard all the cookies, more kids in the neighborhood can trade and buy things.

The bank doesn't create new cookies; it just moves them around quickly.

If everyone tried to get their cookies back at once, the jar would look empty. This is called a bank run. But usually, only a few people need cookies at any moment, so the bank stays safe. This system lets the economy grow because money isn't stuck in a vault; it's working hard, helping people buy bikes, build houses, and start businesses. It’s not magic; it’s careful sharing.