The United Nations is an international organization established in 1945 to promote international cooperation. It currently has 193 member states. The UN aims to maintain international peace and security, protect human rights, deliver humanitarian aid, promote sustainable development, and uphold international law. It provides a forum for member states to discuss issues and negotiate solutions to global problems. However, the UN faces criticisms related to its effectiveness in achieving its goals like maintaining peace and security due to veto powers of permanent Security Council members and issues with achieving consensus among diverse member states.