In the U.S. commonwealth of Pennsylvania, a borough (or a boro) is a self-governing municipal entity, best thought of as a town, usually smaller than a city, but with a similar population density in its residential areas. Boros also tend to have more developed business districts and concentrations of public and commercial office buildings, including court houses. Both are larger, less spacious, more developed than the relatively rural townships—which often have the greater territory and even surround boros of a related or even the same name. There are 958 boroughs in Pennsylvania, but only one town. The alternative spelling "boro" is sometimes used, including official notation.