Suppose you want to buy something but you don't have enough cash with you. You do have money in your checking account, and you have a debit card. A debit is money subtracted from an account. When you use your debit card, money is subtracted from your checking account to pay for something. You can also use a debit card at an ATM (automated teller machine).
A debit card is a plastic card that looks like a credit card, but it works like a check. They are also known as check cards. A credit card is a way to "pay later." A debit card is a way to "pay now." When you use a debit card, the money is subtracted from your checking or savings account almost immediately.
When you use a debit card at a store or restaurant, you or the cashier will slide the card through an electronic machine. The machine reads the card and contacts the bank's computer. The computer makes sure that you have enough money in your checking account to pay for the bill. The bank's computer will then subtract the amount of the bill from the balance in your account. Then the computer sends it to the bank account of the store or restaurant where you made your purchase. The cashier gives you a receipt, which you'll have to remember to record in your checking account register.