Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
Describe what a credit card is.

### Response:
A credit card is a payment card that allows you to make purchases without having to pay upfront. When you use it for a purchase, you are taking out a loan from a bank and the bank pays the merchant for the goods and services you purchased. You then have to repay the loan within a certain amount of time with interest.