A credit card is a small plastic or metal card that lets you buy things now and pay for them later. When you use a credit card at a store or online, the credit card company pays the merchant for you, and then you owe that money to the credit card company. At the end of each month, you receive a bill showing everything you purchased.

Credit cards differ from debit cards, which take money directly from your bank account when you buy something. With a credit card, you're essentially borrowing money each time you make a purchase. If you pay back the full amount by the due date, you don't owe anything extra. But if you only pay part of what you owe, the credit card company charges you interest, which means you end up paying back more than you originally borrowed.

Adults use credit cards for convenience and safety: if someone steals your credit card number, the credit card company can help fix the problem, whereas stolen cash is simply gone. Credit cards can be useful tools, but they require discipline. Because the money doesn't leave your account immediately, it's easy to spend more than you can afford to pay back. People who consistently spend more than they earn can end up owing thousands of dollars and struggling to pay it back, which is why understanding how credit cards work matters long before you ever get one.