Important Terms

First urban revolution: The historical emergence of cities and urbanism.
Urbanism: The pattern of behaviour, relationships and modes of thought characteristic of urban life.

Sociological city: A relatively large dense permanent settlement of socially heterogeneous persons.
Geographic city: The continuously built-up area in and around the legal city.
Legal city: A municipal corporation occupying a defined geographical area subject to a legal control of the state.
Second urban revolution: The historical transformation of a city accomplished by the industrial revolution which turned the city into an industrial centre.
Metropolis: The legal city together with the built up area surrounding it.

Third urban revolution: The urbanization of the entire world population but sometimes specifically used to include the special form of city emerging in the developing nations and the growth of megalopolitan forms of super cities.
Suburbanization: The growth of a ring of relatively small communities around the central city and the movement of urban population to them. Contemporarily associated with urban sprawl and deterioration of the central city.
Suburb: A community on the urban fringe. These are of two types- residential and satellite
Ghetto: An urban ethnic or racial community often confused with slum. A ghetto may also be a slum.
Slum: An urban residential area characterized by over crowding and sub-standard way of living.
Urban concentration: It is the tendency of people and activities to cluster together.
Urban decentralization: When people go away from the centre of the city.
Metropolitan Fringe- It is on the outskirts of many industrial cities which are meant for commuter housing. Distinctive life-styles prevail between middle class commuters and old working class.
Primate city: An urban form now emerging in developing nations where one city dominates the entire society.
Gentrification: Renovation of decaying urban areas for occupancy by middle or upper class residents.