Credit unions, unlike banks, are based on a cooperative or "co-op" model in which the members are also the owners.

This is the biggest difference between credit unions and banks. While a bank is a for-profit company that distributes profits among shareholders or individual owners, a credit union is a not-for-profit institution "owned" by its members. Therefore, you can think of credit union membership as buying a stake in an organization, rather than paying somebody else in exchange for services.