Put simply, Lets say hypothetically he’s like you on lemmy.cafe.
and we’ll say he’s posting to to lemmy.world/c/memes which he was banned from.
His post will show up to lemmy.cafe users connected to memes… but his posts will only show up on the lemmy.cafe version of memes. When cafe federates back to world, world will just ignore the posts and not share them.
In addition they won’t be seen by, lets say programming.dev here, while it hasn’t banned this person, it’s looking to world for it’s copy of the community, which will not have your friends posts.
Kichae@lemmy.ca 1 week ago
So, when you post to a community, you’re posting to the local copy of it. Your host then forwards that post to the site that houses the community. When you’re banned from a remote site, nothing interferes with this process until the local host forwards things along. By that time, you’ve already posted.
Now, the site that’s housing the community is responsible for federating content it receives back out again, so while you can continue to post to the community locally, those posts won’t make it to any other copy of the community. But because each instance’s copy of the community is quasi-independent from each other, you can, IIRC, still engage with other local users in that space.