Län (Swedish) and lääni (Finnish) refer to the administrative divisions used in Sweden and previously in Finland. The provinces of Finland were abolished on January 1, 2010.
They are also sometimes used in other countries, especially as a translation of the Russian word oblast. During the period when Finland was a part of the Russian Empire (1809-1917), when Russian was made an official language alongside Swedish, it was synonymous with the word guberniya.
Read more about Län: The Term, The län, The landsting, The landshövding