The other is that you have no property rights, and you have unlimited use rights. This community is organized and managed, and the final property right is theirs, but they can't just ask you to move out. You have to pay a certain "rent" every month, but other houses with the same conditions are very cheap, and often include utilities or other expenses. Every year, this organization invites companies to do asset appraisal, and then tells all residents the results.
In both cases, the price of the first one will be higher, generally twice that of the second one under the same conditions. So people who haven't decided to live in Denmark for a long time or don't have much savings usually buy the second one.
As for the real estate agent, I don't know. I only know the website of selling houses, but I have summarized the resources of various intermediaries. If you really want to buy it, you still have to contact the intermediary. In addition, if you want to buy a house in Denmark, you must have a residence permit. This is to prevent foreigners from buying all their houses and raising the house price (although it is not low now. . . . . )