Geopolitics (from Greek γῆ gê “earth, land” and πολιτική politikḗ “politics”) is the study of the effects of Earth’s geography (human and physical) on politics and international relations. While geopolitics usually refers to countries and relations between them, it may also focus on two other kinds of states: de facto independent states with limited international recognition and relations between sub-national geopolitical entities, such as the federated states that make up a federation, confederation or a quasi-federal system.