Non-metropolitan districts, or colloquially shire districts, are a type of local government district in England. As originally created, they are sub-divisions of non-metropolitan counties (colloquially shire counties) in a so-called "two-tier" arrangement. In the 1990s, several non-metropolitan counties were created that are unitary authorities and also have non-metropolitan district status. A third category is the districts of Berkshire, which are non-metropolitan districts that are unitary authorities, but without non-metropolitan county status.
Shire districts
Shire districts are subdivisions of English non-metropolitan shire counties which have a two-tier structure of local government. Shire counties have a county council, and also have several districts, each with a district council. Local government functions are divided between county and district councils, to the level where they can be practised most efficiently: