Bank cards are plastic cards issued by financial institutions that allow users to access their bank accounts and make transactions. There are different types of bank cards, including debit cards, which withdraw money directly from a user's account, and credit cards, which allow users to borrow money up to a certain limit for purchases. These cards can be used for various transactions, such as shopping, paying bills, and withdrawing cash from ATMs. Bank cards often come with security features, like a PIN or a chip, to help protect against fraud and unauthorized use.