what are urban areas

An urban area is a human settlement with a high population density and an infrastructure of built environment. Urban areas originate through urbanization and consist of a densely-settled urban core, plus surrounding developed areas that meet certain density criteria. Urban areas include towns, cities, and suburbs. Places administered by a municipal corporation, cantonment board, or notified town area committee are automatically considered urban areas. Urban areas are locations with high population density and have the most human-built structures. The built environment in urban areas creates opportunities for health such as sidewalks and public transit, but it also creates challenges to health such as sedentary commuting and air quality. Urban areas are distinguished from rural areas, and any area not part of an urban area is considered rural. The U.S. Census Bureau designates areas of 2,500 to 50,000 people as Urban Clusters and areas of 50,000 or more people as Urbanized Areas.