Several districts form a "Region" (Slovak "kraj"). One district, on the other hand, consists of several "municipalities" (Slovak "obec"), which in turn consist of "cadastral areas" (Slovak "katastrálne územie").
Districts have been units of state administration in Slovakia since the time of the Habsburg monarchy, except for the period from 2004 to late 2013. Today, each district is administered by a "district office" (okresný úrad). Since late 2013, there have been also some special district offices being responsible (regarding some selected issues) not for the territory of a district, but for the territory of a Region (kraj) - they are called "district office at the seat of a Region" (okresný úrad v sídle kraja).
In the period from 2004 to late 2013, the district offices were abolished and replaced by "circuit offices" (obvodný úrad), which were usually responsible for several districts (except for the Nové Zámky District, which was one district with two circuit offices).
Slovakia has currently 79 districts, the capital of Bratislava being divided into 5 districts and the city of Košice in 4 districts. The districts are named after the biggest town in the district (formerly known as the "district towns").