Urbanization, urbanisation or urban drift is the physical growth of urban areas as a result of rural migration and even suburban concentration into cities, particularly the very largest ones. The United Nations projected that half of the world's population would live in urban areas at the end of 2008.
Urbanization is closely linked to modernisation, industrialisation, and the sociological process of rationalisation. Urbanisation can describe a specific condition at a set time, i.e. the proportion of total population or area in cities or towns, or the term can describe the increase of this proportion over time. So the term urbanisation can represent the level of urban relative to overall population, or it can represent the rate at which the urban proportion is increasing.
Urbanisation is not merely a modern phenomenon, but a rapid and historic transformation of human social roots on a global scale, whereby predominantly village culture is being rapidly replaced by predominantly urban culture. The last major change in settlement patterns was the accumulation of hunter-gatherers into villages many thousand years ago. Village culture is characterised by common bloodlines, intimate relationships, and communal behavior whereas urban culture is characterised by distant bloodlines, unfamiliar relations, and competitive behavior. This unprecedented movement of people is forecast to continue and intensify in the next few decades, mushrooming cities to sizes incomprehensible only a century ago. Indeed, today, in Asia the urban agglomerations of Dhaka, Karachi, Mumbai, Delhi, Manila, Seoul and Beijing are each already home to over 20 million people, while the Pearl River Delta, Shanghai-Suzhou and Tokyo are forecast to approach or exceed 40 million people each within the coming decade. Outside Asia, Mexico City, Sao Paulo, New York City, Lagos and Cairo are fast approaching or home to over 20 million people already.
Read more about Urbanization: Movement, Causes, Dominant Cities, Economic Effects, Environmental Effects, Changing Forms