Specialized agencies are autonomous organizations working with the United Nations and each other through the coordinating machinery of the United Nations Economic and Social Council at the intergovernmental level, and through the Chief Executives Board for coordination (CEB) at the inter-secretariat level. Specialized agencies may or may not have been originally created by the United Nations, but they are incorporated into the United Nations System by the United Nations Economic and Social Council acting under Articles 57 and 63 of the United Nations Charter. At present the UN has in total 15 specialized agencies that carry out various functions on behalf of the UN. The specialized agencies are listed below.