A credit card is a small plastic card issued by a bank or financial institution that allows you to borrow money to make purchases. When you use a credit card, you are essentially taking a loan that you promise to pay back later, usually within a month. If you pay off the full amount by the due date, you often won't incur any interest charges. Credit cards can also offer rewards, such as cash back or travel points, for every dollar spent. However, it's important to use them wisely, as overspending can lead to debt and high interest rates. Always keep track of your spending and make payments on time to maintain a good credit score.