Credit cards are plastic cards that allow users to make purchases now and pay for them later. They provide pre-approved credit up to a set limit. To be eligible, one must have a bank account and be deemed creditworthy based on income, assets, and expenses. Credit cards display key information like the card number, expiration date, security features, issuing bank, and signature strip. They are classified based on payment type, user status, validity area, brand affiliation, and issuing institution. Credit cards offer convenience for users and guaranteed payment for merchants, while banks earn revenue from fees. However, they also carry risks like debt, fraud, and theft for users and merchants. Safety tips include signing cards, reporting loss/theft