But how come some instances show posts from more communities than others? How come i can register the same username multiple times on different instances? How come it's so difficult to subscribe to a community from a different instance?

[–] ayla@discuss.tchncs.de 9 points 1 year ago

you can use the same name because, similar to an email address, the instance is part of your username (eg: asdf@gmail.com is different to asdf@hotmail.com) your app / site may just hide the end part

the subscribing problem might also just be on your app specifically, as i have no problems subscribing

[–] fazey_o0o@lemmy.world 9 points 1 year ago (1 children)

The "showing more communities" part is called federating. basically, an instance (@lemmy.world in ur case) has a bunch of communities. now the owner of that instance can "federate" with another instance, so that you can additionally view their communities as well.

I'm a complete newb with Lemmy as well, but as far as I know, lemmy.world for example only defederated some extremist instances (and threads if I'm not mistaken?)

[–] KSPAtlas@sopuli.xyz 2 points 1 year ago

Beehaw defederated lemmy.world