The document discusses key terms related to urbanization such as millionaire cities, megacities, and world cities. It defines millionaire cities as having over 1 million people, megacities as over 10 million people, and world cities as having great global influence due to financial status and commercial power. Examples given are New York, London, and Tokyo. The document also examines patterns of urbanization, noting areas that urbanized first and are increasing most rapidly, like Africa and Asia. Causes of urban growth discussed include natural population increase and rural-urban migration due to push factors like lack of land and pull factors like employment opportunities.