Since 1949 (except 1990–1996), Slovakia has been divided into a number of kraje (singular kraj; usually translated as "Regions" with capital R). Their number, borders and functions have been changed several times. There are currently eight regions of Slovakia and they correspond to the EU's NUTS 3 level of local administrative units. Each kraj consists of okresy (counties or districts). There are currently 79 Districts.
More information on the Wikipedia page [1].