Key learning points

1. The urban hierarchy explains how settlements range from small villages to global cities based on size and function.
2. Urbanisation is the growth of urban areas and is a phenomenon experienced globally.
3. The location of the biggest cities in the world has changed over time from high to low and middle income countries..
4. The two main causes of urbanisation are rural to urban migration and natural increase.
5. In 2008, for the first time in world history, over 50% of the world's population lived in towns and cities.

Keywords

• Urbanisation - the increase in the proportion of people living in towns and cities

• Natural increase - when a population grows because births outnumber deaths

• Rural to urban migration - the movement of people from the countryside to towns and cities

Common misconception