I'm making flashcards on World War 1 and got to the Female Red Guards of the Finnish Civil War, I continued to read upon the Finnish Civil War and noticed that it talks about the transition of Finland from the Russian Empire to an independent state, a sovereign state, others sometime refer to Finland as a nation or a country but i'm not sure what is correct.
Finland is a nation and was a nation (and a country or course). When they gained independence and sovereignty they became a sovereign state. The difference is just on the wording of your sources.