Urbanization can be defined as the process by which urban areas grow and by which the population of a country comes to be more concentrated in urban areas. This is a process that typically happens to any country as it develops and, particularly, as it industrializes.
As a country develops, it typically comes to be more efficient at raising food. This means that it does not need as many people working on farms. People who are no longer needed on farms often move to cities. As a country develops, it typically starts to have factories. These factories are typically in cities. They attract more people to them because people want to work in those factories. These factors contribute to urbanization.
We can see these processes at work in China today. Their people have been moving from the countryside to the cities for over a decade now. This has led to a great deal of social tension because their government has not dealt well with the problems that come out of urbanization.
Thus, urbanization is the process of urban growth and is a process that can lead to controversy and to problems for a country in the short term.