The world's population is unevenly distributed on earth

http://en.wikipedia.org/wiki/World_population

Few key words:

Population Distribution

economic factors - factors connected with jobs and money
empty lands - areas with low population density
environmental factors - factors connected to the natural environment e.g. climate, relief, soil
political factors - factors to do with the government and the European Union
population density - the number of people per square kilometre of land
population distribution - the way in which a population is spread throughout a country or region
population pyramid - a bar graph which shows the age and sex composition of a population