The federal Deposit Insurance Corporation (FDIC) is an agency of the government that has the duty of protecting consumers and the entire American financial system
Among its functions is, deposit insurance, this, helps consumers of bank services to avoid loses in the event that a bank fails.
Banks are in business with the consumer deposits, this is where they obtain the interest they add on a consumers deposits. Being a business, it might therefore fail. In case of this, the FDIC steps in to the aid of the consumer, to pay the amount the bank owes them.