The Bank Account That Paid Rent on Money
When you keep money in a savings account, the bank does not just lock it in a vault. The bank uses the money that many people save to make loans to others. In return, it pays you a small reward called interest. You can think of interest as rent that the bank pays for borrowing your money.
Interest is figured as a percent of your savings. Suppose you put $100 in an account that pays 5 percent each year. Five percent of $100 is $5, so after one year you would have $105. You did nothing but wait.
Here is the exciting part. Many accounts add the interest to your balance, and then the next year's interest is figured on the bigger amount. In the second year, 5 percent of $105 is $5.25. That is a little more than the first year. The extra grows slowly at first, but over many years it adds up. This is called compound interest.
Real banks change their rates from time to time, so the 5 percent here is only an example. A higher rate gives you more, and a lower rate gives you less. Still, the lesson holds. The longer money stays in the account, the more time it has to earn. Starting early gives your savings the most time to grow.