Lesson 6: Cards: Debit and Credit

Plastic cards have replaced cash for many everyday purchases, but the two main kinds of card work in opposite ways — and confusing them is one of the most expensive mistakes a young person can make. A debit card spends your own money: when you pay, the amount comes straight out of your bank account. If the money is not there, the payment usually fails. A credit card spends the bank's money: the bank pays the shop, and you owe the bank. You must pay the bank back later, and if you do not pay the full amount on time, the bank charges interest on what you still owe — often at a high rate. The card looks the same in your hand, but the two are fundamentally different.

Debit cards are the safer starting point. They let you pay without carrying cash, they cannot push you into debt beyond your balance, and they help you track spending through your bank statement. Their main weakness is that if someone steals your card details, the money leaves your account immediately, though banks usually help recover it if you report the loss quickly. Credit cards have real uses: they are convenient for travel and online purchases, they can help build a record of responsible borrowing (called a credit history), and in some countries they offer stronger protection when goods are faulty or never arrive. But those benefits come with a trap: the ability to buy now and pay later makes it easy to spend money you do not have.

The Credit Card Trap

Here is how the trap works. You buy something for 100 units on a credit card. At the end of the month the bank asks for payment, but offers a choice: pay the full 100, or pay a small 'minimum payment' — perhaps 5 units — and carry the rest forward. Paying the minimum feels easy, but the remaining 95 now attracts interest every month, and new purchases add to it. Month after month, interest is charged on a growing balance, and a purchase that cost 100 can end up costing far more. The exact interest rates and minimum-payment rules vary by country and by card — check your local rules — but the principle is universal: borrowed money is expensive money, and minimum payments are designed to keep you in debt, not to free you from it.

Using Cards Wisely

A few rules keep cards useful and safe. Use a debit card for everyday spending, so you only spend money you actually have. If you ever use a credit card, treat it like a debit card: only buy what you could pay for from your account today, and pay the full balance every month so no interest is charged. Never share card numbers, PINs or security codes, and never let someone photograph your card. Check your statements every month, and report anything unfamiliar at once. Cards are tools, and like any tool they are safe when used with understanding — and costly when used without it.