This article provides insufficient context for those unfamiliar with the subject.(February 2013)
In contrast to centrally organised states, in the federally constituted Switzerland each canton is completely free to decide its own internal organisation. Therefore, there exists a variety of structures and terminology for the subnational entities between canton and municipality, loosely termed districts.
Most cantons are divided into Bezirke (German for districts, singular Bezirk). They are also termed Ämter (Lucerne, singular Amt), Amtsbezirke (Bern, Amtsbezirk), district (in French) or distretto (Ticino and part of Graubünden). The Bezirke generally provide only administration and court organization. However, for historical reasons districts in cantons Graubünden and Schwyz are their own legal entities with jurisdiction over tax and often have their own Landsgemeinde.
Seven of the 26 cantons - Uri, Obwalden, Nidwalden, Glarus, Zug, Basel-City and Geneva - have always existed without the district level of government. An eighth one, Appenzell Innerrhoden, uses no intermediate level either, but calls its lowest-level subdivisions Bezirke, although they are functionally equivalent to municipalities elsewhere.
A number of further cantons are considering (or have already decided) an abolition of the district level in the future: Appenzell Ausserrhoden, Schaffhausen, Lucerne, St. Gallen, Schwyz in 2006 voted on its abolition, but voted in favour of keeping the division, some with modifications. Bern in 2006 decided a reduction of its 26 districts to ten administrative regions, which took effect in 2010. St. Gallen, Solothurn and Lucerne removed the administrative role, but retained districts for elections. In 2008 Vaud decided on a reduction from 19 to 10 districts, followed by Thurgau which combined eight into five in 2012. In 2017 Graubünden replaced the 11 districts with 11 regions. In 2018 Neuchâtel eliminated the district level.
For further updated about this districts, see: Population size and population composition - Data, indicators: Cantons, communes  or Permanent resident population by age, canton, district and commune 2010-2013.
The Canton of Zürich is divided into 12 districts (German: Bezirke):
The Canton of Bern is divided in five regions: Berner Jura, Seeland (with two subregions, Biel/Bienne and Seeland), Bern-Mittelland, Oberland (with subregions Thun, Obersimmental-Saanen, Frutigen-Niedersimmental, Interlaken-Oberhasli) and Emmental-Oberaargau (with two subregions, Emmental and Oberaargau) The current division has taken effect on 1 January 2010, based on a 2006 decision to abolish the former system of districts.
On 1 January 2010, the 26 administrative districts (Amtsbezirke) were combined into 10 new administrative districts (Verwaltungskreise):
The Canton of Lucerne used to be divided into 5 Ämter:
These were abolished with the new cantonal constitution of 2007, although they will continue to be used as electoral districts.
The Canton of Schwyz is divided into 6 districts:
The Canton of Fribourg is divided into 7 districts:
From 2005, Solothurn's ten districts are merged pairwise into five electoral districts, termed Amtei. From 2005, districts only have a statistical meaning.
Basel-Landschaft is divided into 5 districts:
The canton abolished the district level in 2003, but it remains divided into eight constituencies (Wahlkreise) without administrative significance:
Beginning in 2017 Graubünden is divided into 11 regions:
Aargau is divided into 11 districts:
Thurgau is divided into five districts (eight prior to 2011) and each is named after its capital:
Ticino is divided into 8 districts:
Vaud is divided into 10 districts:
Valais is divided into 13 districts:
The district of Raron is divided into:
The Canton of Jura is divided into 3 districts:
The Canton of Schaffhausen is divided into 6 districts:
The Canton of Appenzell Ausserrhoden is divided into 3 districts:
In Appenzell Innerrhoden districts are the lowest administrative division as the canton has no municipalities (except for the Feuerschaugemeinde, a special-purpose municipality for the town of Appenzell). The districts are functionally equivalent to municipalities elsewhere in Switzerland, and are generally shown as municipalities on maps etc.
The Canton is divided into 6 districts: