UN agencies

The United Nations System consists of the United Nations, its subsidiary organs (including the separately-administered funds and programmes), the specialized agencies, and affiliated organizations. The executive heads of some of the United Nations System organizations and the World Trade Organization, which is not formally part of the United Nations System, have seats on the United Nations System Chief Executives' Board for Coordination (CEB). This body, chaired by the Secretary-General of the United Nations, meets twice a year to co-ordinate the work of the organizations of the United Nations System.

The United Nations System includes the United Nations and its subsidiary bodies (such as the separately-administered funds and programmes, research and training institutes, and other subsidiary entities), specialized agencies, and affiliated organizations. Some of the organizations of the United Nations System predate the founding of the United Nations in 1945 and were inherited after the dissolution of the League of Nations.

The principal organ of the UN System was the United Nations itself. It consists of the six principal organs established by the Charter of the United Nations:

The United Nations General Assembly (UNGA/GA) is one of the six principal organs of the United Nations and the only one in which all member nations have equal representation. Its powers are to oversee the budget of the United Nations, appoint the non-permanent members to the Security Council, receive reports from other parts of the United Nations and make recommendations in the form of General Assembly Resolutions. It has also established a wide number of subsidiary organs.

The United Nations Security Council (UNSC) is one of the principal organs of the United Nations and is charged with the maintenance of international peace and security. Its powers, outlined in the United Nations Charter, include the establishment of peacekeeping operations, the establishment of international sanctions, and the authorization of military action. Its powers are exercised through United Nations Security Council resolutions.

...
Wikipedia