The growth of modern cities began in Europe in the latter half of the 18th century. The urbanization of developing countries began properly only during the 1950s.
Approximately 4 billion people live in cities around the world.
Cities grow into metropolises, megacities, and megalopolises.
Uncontrolled urbanization has had various negative side effects, such as urban decay, unemployment, crime, and increased pollution.
Urbanization also has its benefits. Cities provide a large number of jobs and services.
The growth of modern cities began in Europe in the latter half of the 18th century. The urbanization of developing countries began properly only during the 1950s.