International organization is a foundational concept in international studies, referring to formal institutions established by agreement among states or other international actors as subjects of academic inquiry. This field investigates their structure, functions, decision-making processes, and impact on state behavior and global governance. Key characteristics include their basis in international agreements, defined membership, and established institutional structures designed to facilitate cooperation, manage interdependence, and address shared challenges, highlighting their significance in shaping international norms, policies, and outcomes.