Districts are a type of administrative division

Administrative division

An administrative division, subnational entity, or country subdivision is a portion of a country or other political division, established for the purpose of government. Administrative divisions are each granted a certain degree of autonomy, and are required to manage themselves through their own...

, in some countries managed by a local government

Local government

Local government refers collectively to administrative authorities over areas that are smaller than a state.The term is used to contrast with offices at nation-state level, which are referred to as the central government, national government, or federal government...

. They vary greatly in size, spanning entire regions or counties, several municipalities

Municipality

A municipality is essentially an urban administrative division having corporate status and usually powers of self-government. It can also be used to mean the governing body of a municipality. A municipality is a general-purpose administrative subdivision, as opposed to a special-purpose district...

, or subdivisions of municipalities.
In Austria

Austria

Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...

, a district or Bezirk is an administrative division normally encompassing several municipalities

Municipality

A municipality is essentially an urban administrative division having corporate status and usually powers of self-government. It can also be used to mean the governing body of a municipality. A municipality is a general-purpose administrative subdivision, as opposed to a special-purpose district...

, roughly equivalent to the Landkreis in Germany. The administrative office of a district, the Bezirkshauptmannschaft is headed by the Bezirkshauptmann.