"Urbanisation is a population shift from rural to urban areas, "the gradual increase in the proportion of people living in urban areas", and the ways in which each society adapts to the change. It is predominantly the process by which towns and cities are formed and become larger as more people begin living and working in central areas. Rapid urbanisation presents new and substantial challenges, ranging from governance and citizenship to infrastructure, housing, and the environment. Urban planning is a technical and political process concerned with the use of land, protection and use of the environment, public welfare, and the design of the urban environment, including air, water, and the infrastructure passing into and out of urban areas such as transportation, communications, and distribution networks. This book focuses on key issues that emerge in rapidly growing cities of the developing world."