This document provides an overview of key concepts in world regional geography, including the natural environment, human geography, political geography, and economic geography. It discusses the major divisions of the natural environment like oceans and atmosphere. It describes human geography as the study of people and communities across space and place. Political geography examines how political processes influence and are influenced by spatial structures. Economic geography looks at the location and organization of economic activities, including the primary, secondary, tertiary and quaternary sectors of the world's economy.