The United Nations was formed in 1945 after World War II to promote international cooperation and prevent future wars. It is made up of 192 member states and has headquarters in New York City. The UN aims to protect human rights, deliver humanitarian aid, uphold international law, and maintain international peace and security through organizations like the Security Council and peacekeeping forces. However, the UN faces challenges in fully achieving its goals due to limitations of its powers and lack of unanimous support from member states.