I'm posting, but I have no idea what I'm doing. I don't think I 'get' Lemmy. Do all the dozens of instances have their own versions of communities and conversations? What's the connection? 🤷
It's like email. You have an account on one server and can post to communities on that server. But you can also post to communities on other servers unless they are blocked.
Same way a Gmail user can send emails to other Gmail users but can also send emails to Hotmail users or any other email server user (unless they are blocked).
A community has a handle—like [email protected]—that is unique. The nostupidquestions community belongs to the lemmy.world server, but anyone from any other server can subscribe to the community, and users from any federated server can follow and comment. The comments are global and shared between all federated servers.
I might be completely in the wrong, but here's how I've understood it: imagine that a Facebook user could comment and post on Twitter with only their Facebook user. They are federated.