Very similar. The Swedes think they are much better. The Norwegians too of course.
Us Swedes used to call the Norwegians 'little poor brothers across the mountains'
Then the Norwegians found Oil and gas in immense amounts, the fish they catch and cultivate became sought after and profitable.
Most of the Swedish industry got sold or moved, so I am not so sure what they say these days.
The Norwegians do not say much, they just smile........
It could be one country, easily. Used to be a Union, but the Swedes treated the Norwegians quite badly, so the union split in 1905.
So, very similar. Each country have large cultural differences south-middle- north, I would say as much difference as between the countries.
My family in Stockholm, and my friends all over Sweden tell me the country has changed a lot since 2015. To the worse. Much worse.
But that can be seen as politics, so I am not going there!
Nature is more beautiful in Norway. Fishing too. And it is not as nut shrinkingly cold in Norway as in Sweden. The Atlantic moderates it.
Historically, todays Norway and Sweden were a bunch of interconnected, independent kingdoms until the early Viking age, Then the kingdoms started joining each other. Norway became one country before Sweden became one. Then Noprway became a part of Denmark.
Sweden.
Sweden took Scania ( southern bit) from Denmark in 1658, the Treaty of Roskilde, and became Sweden as we are now/
So, in short, very similar.
In my opinion of course.
Most people with a Swedish/Norwegian schooling speak decent English.
Food is very similar too. (Norwegian bread is awful though, imo).
Sweden has much larger 'empty' areas, hence my standard recommendation on this forum to go to Sweden to spend time in Nature. And Norway for the fishing.
Personally I prefer Norway. Hence my twice yearly trips to the Lofotens. For me: Lofotens = Nirvana.
My Norwegian friends are OK with that I am Swedish. They stopped beating and bullying me once they realized I plan to retire to the village.