a certificate of deposit (cd) is a way to store money at a bank or credit union. a cd is written for a period of time: usually between three months and five years. the person who wanted the cd—the consumer—agrees to give the money to the bank for that period of time and may not take the money back until the time has expired. if the consumer takes the money back before the agreed amount of time, they will have to pay a penalty fee. once your contract is over, you are given your money back plus the interest it earned. people open cds instead of savings accounts because the interest is higher. a certificate of deposit (which is common only in the united states) is similar to a time deposit.