A city is a large human settlement. Cities generally have extensive systems for housing, transportation, sanitation, utilities, land use, and communication. Their density facilitates interactionbetween people, government organizations and businesses, sometimes benefiting different parties in the process.
Historically, city-dwellers have been a small proportion of humanity overall, but following two centuries of unprecedented and rapid urbanization, roughly half of the world population now lives in cities, which has had profound consequences for global sustainability. Present- day cities usually form the core of larger metropolitan areas and urban areas—creating numerous commuters traveling towards city centers for employment, entertainment, and edification. However, in a world of intensifying globalization, all cities are in different degree also connected globally beyond these regions.
The most populated city proper is Shanghai while the most populous metropolitan areas are the Greater Tokyo Area, the Shanghai area, and Jabodetabek (Jakarta). The cities of Faiyum, Damascus, and Varanasi are among those laying claim to longest continual inhabitation.