what does it mean that Beehaw "defederated" from lemmy.world?

https://lemmy.world/post/156955

what does it mean that Beehaw "defederated" from lemmy.world? - Lemmy.world

I thought I understood, but I still have Beehaw content in my feed, so I guess I don’t understand after all… Can someone dumb it down for me?

Lemmy.world still has all the content it pulled from beehaw before they defederated, but they won't sync anymore, so you won't see new beehaw posts, and they won't see any posts, comments or upvotes from lemmy.world
Was there a reason why they defederated??
https://beehaw.org/post/567170
This link doesn't work anymore

want a better space, and we think this is necessary to do that right now. if you disagree we understand that, but we hope you can if nothing else come away with the understanding it was an informed decision.

this is also not a permanent judgement (or a moral one on the part of either community’s owner, i should add–we just have differing interests here and that’s fine). in the future as tools develop, cultures settle, attitudes and interest change, and the wave of newcomers settles down, we’ll reassess whether we feel capable of refederating with these communities.