At the beginning of the 21st century we have to face the escalation of urban population and unprecedented urban growth all around the world. Our planet is becoming more and more urbanized. Such development presents a range of opportunities and various stresses to the urban population. In a simplified way, the word urban refers to a specific organization and use of land and space, social and economic settings and environment, to a characteristic way of human habitat. Still, a considerable number of urban inhabitants lack access to the benefits which living in a city may promise: services, infrastructure, social protection and citizen rights.
According to UN-Habitat it is estimated that one third of the global population do not live in adequate conditions and lack access to safe water or sanitation. Those called the urban poor occupy marginal, overcrowded land in informal settlements or dwell on pavements lacking basic services and stable livelihood. It is necessary to rise to the global challenge of recent growth of cities and to search for a sustainable way to manage for future.