When you use a debit card, money that have earned in your account, is being taken out and spent on whatever you are buying. So if I have $25 in my bank account and I buy a case for my cellphone that is $5, then I would have $20 left in my account.
Credit cards are a lot more intricate, but basically you are borrowing money, in which you have to pay back every month, with an interest tax on it, which means that they are charging you for borrowing the money (that is how they make their money). Every month you receive a credit card bill, which will provide you with the fee you have to pay. There different types of credit cards which hold certain amounts of money, such as a $500 credit card, $1,000 credit card, etc., but it is best to purchase the lowest credit card that holds the least amount of money and a low interest rate so you can pay them back. If you do not, then you will enter the death hole, which destroys your credit score; if you do pay them back, your credit score will strengthen.
