In the United States, a charter city is a city in which the governing system is defined by the city's own charter document rather than solely by general law. In states where city charters are allowed by law, a city can adopt or modify its organizing charter by decision of its administration by the way established in the charter. These cities may be administered predominantly by residents or through a third-party management structure, because a charter gives a city the flexibility to choose novel types of government structure. Depending on the state, all cities, no cities, or fewer than all cities may be charter cities.