Question about the Kalmar Union

So... I'm a bit confused here, and apologies if this is a dumb question, I legitimately don't know this.

Was the Kalmar Union just a personal union, meaning Sweden and Norway are technically independent states, simply sharing the crown with Denmark, or was it an actual state, meaning that Sweden and Norway were actually a part of the Danish realm?

So, this is not my area of expertise, but from what I could glean reading (very, very briefly) is that Sweden, Norway, and Denmark operated as independent states with the exception that certain realms were reserved for a single monarch. Those areas were foreign and domestic policy.

There are definitely people on the forum who can give a better answer, but I figured that is a starting point.

The "Kalmar Union" simply refers to the personal union. Sweden and Norway were not part of Denmark during the Kalmar era. From what I've seen, during most personal unions, the subject state(s) act as sovereign entities; the monarch controls all foreign policy decisions and some domestic policies like taxation and military conscription. I have seen nothing to suggest the Kalmar Union worked any differently.

However, after Sweden broke out of the Union, Norway still remained under Denmark. They would be fully integrated into the Danish realm in 1660, forming a country called Denmark-Norway. So Norway eventually became part of Denmark, just not under the Kalmar arrangement.