A bank holding company is a company that owns one or more banks. The purpose of a bank holding company is to provide support and guidance to its affiliated banks. They often provide financing, advice, and other services to their subsidiaries. A bank holding company can be national or state-chartered banks, commercial banks, savings and loan associations, or credit unions. The Federal Reserve Board must approve the formation of bank holding companies. The Board also regulates the activities of bank holding companies to ensure that they comply with banking laws and regulations.