Common region names
The name Scandinavia come from the Skandage body of water sandwiched between Norway, Sweden, and Jutland. The culture of Scandinavian countries are very close and the languages mutually intelligible. In writing, the difference between the Danish and Norwegian languages are not much bigger than the difference between English and American English, though it will often be harder in oral conversations. Swedish is slightly different from the other two but is more similar to spoken Norwegian than is spoken Danish. The Scandinavian languages are North Germanic, strongly influenced by Low Saxon (Ancient German).
The Finno-Ugric language of Finland is entirely unrelated with Scandinavian language, although most people in Finland also speak some Swedish, as the country is officially bilingual and all Finns learn Swedish in school. The language of Iceland is actually Old Norse (spoken in Scandinavia 1000 years ago and also closely related to Old English), other than a few words that are now spelled differently. Iceland was a Norwegian and then Danish colony until 1944.
The ScanRail pass offers unlimited train travel in Denmark, Finland, Norway and Sweden.
The 5-day Flexipass is valid only for 15 days if purchased in Scandinavia, and the 10-day version can only be purchased outside. In addition to free travel in the region, you can also take night trains to/from Berlin (Germany) with the pass.