The districts of England are a level of subnational division of England used for the purposes of local government. As the structure of local government in England is not uniform, there are currently four principal types of district-level subdivision. There are a total of 326 districts made up of 36 metropolitan boroughs, 32 London boroughs, 201 non-metropolitan districts, 55 unitary authorities, as well as the City of London and the Isles of Scilly which are also districts, but do not correspond to any of these categories. Some districts are styled as boroughs, cities, or royal boroughs; these are purely honorific titles, and do not alter the status of the district. All boroughs and cities, and a few districts, are led by a mayor who in most cases is a ceremonial figure elected by the district council, but – after local government reform – is occasionally a directly elected mayor who makes most of the policy decisions instead of the council.