An IGO is a structure based on a formal instrument of agreement between nations (e.g. the United Nations, the EU).
A politico-economic union of member states that are primarily located in Europe.
An international organization of member states committed to maintaining international peace and security, developing friendly relations among nations and promoting social progress, better living standards and human rights.
NGOs are private non-profit organizations that focus on government related topics such as agriculture, the status of women, economic indicators, etc.