What is a credit card?

A credit card looks just like a debit card. However, instead of having the funds removed directly from your checking account when you make a purchase, you’ll essentially take on a short-term loan. This loan may or may not accrue interest, depending on when you pay it off.

For the purchases made in any given billing cycle — which is around 30 days — you’ll have a small grace period before your payment is due. If you pay the balance in full by that date, you won’t have to pay interest. If you pay less than the entire balance by the due date, you’ll accrue interest on your average daily balance.

Source: https://www.nerdwallet.com/blog/11-credit-card/#emv