What does a circle with a star usually mean on a map

A star or star within a dot on a map usually meansthat it is the location of a capital city, whether in a state or a country. The star is typically located on the legend in one of the corners of the map to indicate the symbol's meaning.

An informal structure in a bureaucracy would be something like so-called "office politics". where there's a formal structure set up for the organization, but then an informal subculture as well that has a way of organizing the bureaucracy further. this can be positive because it sets up an added degree of organization, albeit informal, within the bureaucracy.