organization established by treaty between governments
An international organization is an organization, active in more than one country. These organizations can not command countries and citizens in a way a government can. Many are intergovernmental organizations meaning that rather than having people as members, they have individual countries as members. They make rules that the different governments follow. The United Nations is such an organization.
Some International organizations operate in many countries but do not have governments as members. The Red Cross is that kind of organization.