An intergovernmental organization, also known as an international organization or an international institution, is an organization that is established by a treaty, or is an instrument governed by international law and possessing its own legal personality1. These organizations are composed primarily of member states, but may also include other entities, such as other international organizations, firms, and nongovernmental organizations2.
Notable examples of intergovernmental organizations include the United Nations (UN), World Health Organization (WHO), Save the Children International, International Union for Conservation of Nature, and NATO3. These organizations are sometimes referred to as intergovernmental organizations (IGOs) to distinguish them from international non-governmental organizations (INGOs), which are non-governmental organizations (NGOs) that operate internationally4.
IGOs are established by a treaty that acts as a charter creating the group. Treaties are formed when lawful representatives (governments) of several states go through a ratification process, providing the IGO with an international legal personality5. Intergovernmental organizations are an important aspect of public international law6.