What does urbanization refer to?

Urbanization refers to the movement of people to urban areas, which typically leads to the growth of cities and metropolitan regions. This process is characterized by an increase in the proportion of a population living in urban settings, often accompanied by significant social, economic, and environmental changes. As more individuals migrate from rural to urban areas in search of better opportunities, urban centers expand and transform in terms of infrastructure, services, and cultural dynamics.

In understanding this concept, it's important to recognize that urbanization has profound implications, such as changes in employment patterns, housing developments, and the creation of diverse communities. The other options do not accurately capture the essence of urbanization: an increase in rural population would indicate a move away from urbanization, the transformation of agriculture-based societies relates more to economic shifts rather than specifically to urban movement, and the decline of urban centers is the opposite of what urbanization represents. Thus, the definition focuses on the trend of increasing population density in urban areas, which is accurately reflected in the correct choice.