Take Baoshan, for example. When one looks at the region surrounding Baoshan, one sees "Baoshan" on the map. Zoom in any further, though, and the city seems to disappear. It suddenly becomes Longyang. Zoom in some more and one can see the Baoshan airport, but there is no obvious city of Baoshan. What gives?
Well, it turns out that it has to do with the regional and local levels of government, and the way those administrative divisions are displayed on the map. Baoshan and Kunming are what are called "prefecture-level cities." Think of a prefecture-level city as what would be the county surrounding a major city in the U.S. For example, Chicago is in Cook County. If it were a prefecture-level city in China, Cook County would be what is called Chicago. Within the prefecture-level city would be urban centers and possibly rural surroundings, but all of it would be called "Chicago."
The librarian in me wants to know how Baoshan compares to other metropolitan areas in the U.S. Baoshan prefecture-level city covers an area of nearly 20,000 square km (~7,700 sq. miles) and has a population of about 2.5 million, about the same as the Denver-Aurora-Broomfield metropolitan area. The Longyang district of Baoshan, the urban center of the prefecture-level city, has a population of 850,000, or about the same population as the Albany-Schenectady-Troy metropolitan area or the city of San Francisco. Kunming prefecture-level city has a population of 6.8 million with an urban population of over three million--the 23rd largest in China--which would make it the third largest city in the U.S.