Complex, modern cities must have both form and function. A city may have a beautiful system of tree-lined boulevards or an easily navigable street grid, but these elements of form are useless if the city does not also have a way to perform such basic functions as keeping these streets clean or passing laws to regulate their use. The last chapter explored how the city can be viewed as a collection of infrastructure networks-streets, but also power lines, water pipes, and other conduits-that together give cities their distinctive physical forms. Complementing this perspective, this chapter examines how cities can also be viewed as a collection of networks among organizations-for example, city hall is linked to the county courts, or the high school is linked to the YMCA-that together allow cities to coordinate and perform practical functions.