Social and economic indicators of development influence population growth including birth rates and death rates whilst physical and human factors affect population distribution in a country.
According to the United Nations, it is estimated that in 2008, for the first time, more people lived in cities than in rural areas.
This is expected to increase to 53 per cent in 2015 and to 60 per cent in 2030, when the percentage of people living in urban areas in developing countries will be more than 50 per cent.
In general, people all over the world are moving from rural areas to urban areas, and cities are continuing to grow.
In developing countries more people still live in rural areas, as there are large numbers of people working in primary industries such as farming, whereas in developed countries most people are employed in service industries, eg offices and provide services in urban areas.