Translation:The west coast is the front side of Sweden.
Militarily speaking, that may be true today... https://taskandpurpose.com/mandatory-fun/fake-swedish-officer-nato-hq Supposedly, the fake officer didn't share (w/ Russia or anyone else) any intel he gathered while in Afghanistan working "on an intelligence system operation used by more than 48 nations to share "surveillance and reconnaissance information.""
In English, the front side of a building is the side you would normally see first, the most important part of a building, the side where the front door is located and the most frequently used door into the house. In our old towns, the importance of the front side was evident in the construction of a special facade, an appearance much more attractive than the other sides of a building.
For a country, the location of the most traffic would be the "front side," so to speak, and the busiest port might be considered "the front door."
Most English speakers would understand "framsida" best by thinking about the front page of a newspaper. News that might not seem significant but is important to someone and then found on the front page would prompt a squeal of delight and a desire to celebrate. It is my understanding that, in Sweden, the front page of a newspaper or the front cover of a book is considered the front side of the item, so it might be a good idea to learn "framsida" in the context of a newspaper.
But referential to Swedish culture. Gothenburgers often like to refer to their city as the front side of Sweden, since it faces the west onto which Sweden is turned economically, politically and culturally. Also, it's a bypoint that that would make Stockholm the rear end... Which we Stockholmers of course violently refuse. But we're got insults for them too, mostly fish-based, so I guess it evens out. :D
The Stockholm area has some significant ancient history, especially the Gamla Upsala and Sigtuna sites. An argument could be made that the east coast, with its superior length and its history as a Viking center involving much "front door" connections with the Rus roots in what is now northern Russia, especially Old Novgorod, is really the front-side of Sweden. Of course, the Danes have ancient roots in the west coast of Sweden and would like to claim their history as primary. Perhaps Sweden's "front door" has shifted back and forth through history, and so both have a claim to this distinction.
This regional competition for fame is interesting, and I am so glad that duolingo is introducing us to Swedish culture via this vocabulary -- framsida! Because of the various uses of this word in the duolingo exercises, I will always remember the connotations.
Gothenburg is the only non-British city I've come across that seems to have 'British pubs' rather than 'Irish pubs'. There's a pub in the central station actually called Little London, and I had a very passable fish and chips in another one. As a Londoner myself, it certainly makes for a strange experience when visiting there...
Yes, I get what it means in Swedish - I am saying the English sentence should be changed. Translating it into English literally doesn't make sense is my point. Saying that "all Swedes have heard this" doesn't change the fact that the English translation is unnatural. Like MrPitcher has said above, perhaps using something like "main coast" makes more sense. For example, "so-so" in Mandarin is literally "horse horse tiger tiger" (馬馬虎虎), but I don't insist on saying "No, every Mandarin speaker will know that if I say horse horse tiger tiger in English they know what what I mean."
So, I love sentences like this: they really just don't translate smoothly to English. Why? Swedes are culturally distinct from English speakers. They are bound to think and feel in different ways that may not correlate to English. This is where things get interesting for me! I love learning about how people experience the world in ways I haven't yet.
I think the phrase/term itself got popularized by an online video, but I haven't seen it, so I can't say for sure. Making fun of different parts of Finland through stereotypes and the like is an age-old joke though, and those exist for practically everybody, not just Turku.