Denmark is divided into five regions, which contain 98 municipalities (Danish: kommuner, sing.: kommune). This was established per an administrative reform, effective Monday January 1, 2007 which replaced the counties (amter) with five regions (regioner). The 270 municipalities were consolidated into 98 larger units, most of which have at least 20,000 inhabitants. The reason was to give the new municipalities greater financial and professional sustainability. Many of the responsibilities of the former counties were taken over by the enlarged municipalities. 32 of the former municipalities did not merge into larger units, either because they already had merged (2 newly created municipalities) or had a population larger than 20,000 or because they signed a cooperation agreement with a larger municipality.
The archipelago of Ertholmene is not part of any municipality, but is administrated directly by the Ministry of Defence.
More information on the Wikipedia page .