UN is an international organisation whose members are sovereign states. It is nearly universal in its membership, jurisdiction and global objectives. It is dedicated primarily to strengthening of international peace and security, adherence to the principle of equality and self-determination of peoples (decolonisation), development of friendly relations between states and international co-operation in resolving economic, social, cultural and humanitarian problems, including the protection of human rights and fundamental freedoms. To this end, a wide network of international organisations has been set up. These organisations have the status of UN specialised agencies or fit into the UN system. The headquarters of the UN Secretariat is in New York, while other parts of the system are located all over the world, for instance in Geneva, Vienna, Rome, Nairobi, the Hague, Athens, Tokyo and Copenhagen.
The UN was established in 1945, when representatives of 50 countries met in San Francisco at the UN Conference to draw up the United Nations Charter. The UN officially came into existence on 24 October 1945, when the Charter was ratified by China, France, the Soviet Union, the United Kingdom, the United States and by a majority of other signatories. This day is celebrated as the United Nations Day. Today, the UN numbers 192 Member States.
The UN has 6 main bodies: the General Assembly, the Security Council, the Economic and Social Council, the Trusteeship Council, the Secretariat and the International Court of Justice. These bodies differ in importance, responsibility and decision making authority, which is reflected in their mutual relations.