Urbanization is a term that does not only mean the population growth and expansion of urban areas. Urbanization also comprises the processes through which the lifestyles and economic structures of populations become more urban.

As modernization progresses, jobs in the industrial and service sectors become more common. This takes place at the expense of agricultural jobs available in rural areas. When the balance between the amount of jobs available in these different sectors changes, the economic structure of a population becomes more city-focused.

The lifestyle of urban populations is visible in the large amounts of pedestrian and vehicle traffic on the streets of metropolises at rush hour. Compared to life in rural areas, life in cities is distributed more evenly throughout all 24 hours of the day.

The photograph below shows the densely populated area of Manhattan in southern New York. It is characterized by its harbor and tall scyscrapers. A bridge connects Manhattan with Brooklyn.