The United Nations (UN) was founded in 1945 to replace the League of Nations and promote international cooperation. It has six main administrative bodies: the General Assembly, Security Council, Economic and Social Council, International Court of Justice, Trusteeship Council, and Secretariat. The UN works to maintain peace and security, protect human rights, and cooperate on issues like health, development, and the environment through various specialized agencies. While the UN has had some successes, it also faces challenges in areas like terrorism, nuclear proliferation, and responding to humanitarian crises due to veto powers and members' unwillingness to intervene. Overall, the UN aims to prevent war and create conditions for global peace and prosperity.