For example !memes@lemmy.world lists some sister communities. Are sister communities just communities with related topics? Also some communities have partner communities, does this refer to the same thing?
Generally, yeah, just related topics. But there might also be mods that mod both communities.
I don’t think there’s any official distinction but what seemed to be an informal convention I noticed on Reddit was that sister communities were related topics (probably with some coordination/agreement among the communities’ mods) whereas partner communities tended to be related topics that had the same mod(s). Usually the latter might be something where any individual community would be less active so it would be easier for someone to moderate multiple communities.
For an example using music styles, maybe c/ClassicRock might list c/ClassicPunk, c/PsychedelicRock, and c/Prog as sister communities. If someone modded c/PinkFloyd, c/TheWho, and c/DeepPurple they might be listed as partner communities.
If someone modded c/PinkFloyd, c/TheWho, and c/DeepPurple they might be listed as partner communities.
That’s a lot of administration to do when a mod stops or a mod is added.
I’ve assumed they don’t necessarily all have the same mods, and are usually much smaller, niche communities that on Reddit at least wouldn’t see much traffic and wouldn’t necessarily have to worry about spam the way the fediverse does. And I could be making up a distinction between sister/partner communities that doesn’t actually exist just going from my own assumptions.