*197. Boroughs and "Cities."*--The standard type of municipal unit is the borough. Among boroughs there is a certain amount of variation, but the differences which exist are those rather of historic development and of nomenclature than of governmental forms or functions. There are "municipal" boroughs, "county" boroughs, and cities. Any non-rural area upon which has been conferred a charter stipulating rights of local self-government is a borough. Areas of the sort which have been withdrawn from the jurisdiction of the administrative counties in which they are situated are county boroughs; those not so withdrawn are municipal boroughs. The term "city" was once employed to designate exclusively places which were or had been the seat of a bishop. Nowadays the title is borne not only by places of this nature but also by places, as Sheffield and Leeds, upon which it has been conferred by royal patent. Save, however, in the case of the city of London, where alone in England ancient municipal institutions have been generally preserved, the term possesses no political significance.[271] The governments of the cities are identical with those of the non-city boroughs. It is to be observed, further, that whereas formerly the borough as organized for municipal purposes coincided with the borough as constituted for purposes of representation in Parliament, there is now no necessary connection between the two. An addition to a municipal borough does not alter the parliamentary constituency. [Footnote 271: See p. 190.]