An intergovernmental organization whose purpose is to maintain international peace and security, develop friendly relations among nations, achieve international cooperation, and be a center for harmonizing the actions of nations.

It is the world's largest and most familiar international organization.

The UN is headquartered on international territory in New York City, and has other main offices in Geneva, Nairobi, Vienna, and The Hague (home to the International Court of Justice).

The United Nations is part of the broader UN system, which includes an extensive network of institutions and entities. Central to the organization are five principal organs established by the UN Charter: the General Assembly (UNGA), the Security Council (UNSC), the Economic and Social Council (ECOSOC), the International Court of Justice (ICJ) and the UN Secretariat. A sixth principal organ, the Trusteeship Council, suspended operations on 1 November 1994, upon the independence of Palau, the last remaining UN trustee territory.

Four of the five principal organs are located at the main UN Headquarters in New York City, while the ICJ is seated in The Hague. Most other major agencies are based in the UN offices at Geneva, Vienna, and Nairobi; additional UN institutions are located throughout the world. The six official languages of the UN, used in intergovernmental meetings and documents, are Arabic, Chinese, English, French, Russian, and Spanish.

On the basis of the Convention on the Privileges and Immunities of the United Nations, the UN and its agencies are immune from the laws of the countries where they operate, safeguarding the UN's impartiality with regard to host and member countries.