Step 1: Understanding the Concept:
Population distribution means how people are spread unevenly across the earth's surface, with some regions crowded and others almost empty. Several physical, economic, social and political factors together decide this pattern.
Step 2: Physical (geographical) factors.
Climate draws people to mild, temperate zones and pushes them away from extreme heat, cold or aridity. Relief favours flat plains and river valleys, which are easy to farm and build on, over steep mountains. Availability of water and fertile soil supports dense farming populations, as seen along the Nile, Ganga and Yangtze valleys.
Step 3: Economic factors.
Areas with industries, trade, mining or good transport links attract people looking for jobs, which is why industrial regions of Europe, North America and coastal East Asia carry very high population densities.
Step 4: Social and cultural factors.
Regions with better health care, education and social security draw and hold larger populations, while religious or cultural significance can also pull settlers to certain cities and pilgrimage centres.
Step 5: Political factors.
Government policy, such as building new capital cities, resettlement schemes, or restricting movement into border and strategic zones, can raise or lower population in specific areas independent of natural conditions.
Final Answer:
Population distribution across the world is shaped together by physical conditions (climate, relief, water, soil), economic opportunity, social facilities and government policy, which is why some regions are densely peopled and others remain almost empty.\[ \boxed{\text{Physical + economic + social + political factors}} \]