What term is used to describe the increase in the number of people residing in urban areas?

The term that best describes the increase in the number of people residing in urban areas is urbanization. Urbanization refers to the process through which an increasing percentage of a population comes to live in urban areas, often driven by migration from rural to urban settings in search of better economic opportunities, services, and living conditions. It encompasses not just the growth of cities and towns, but also the social, economic, and cultural transformations that occur as more people settle in these densely populated regions.

Urban growth, while related, tends to focus specifically on the physical expansion of urban areas in terms of land area and infrastructure rather than the demographic changes associated with people moving from rural to urban environments. Suburban expansion refers to the growth of suburban areas, which typically involves population movement from urban centers to neighboring suburban regions. Rural decline specifically deals with the reduction in population in rural areas, often as a consequence of urbanization, but does not encapsulate the process of increasing urban population itself.