You have to register to post on the original version of a thread, correct. But federation essentially just trades continually updated copies of the same thread back and forth between different servers. Which is how you're reading this. I'm not even using Lemmy at all, much less lemmy.world specifically. I'm on kbin, and here I am commenting.

Kbin.social has received and delivered unto me a copy of this thread and informed lemmy.world I've commented something in response. Lemmy.world has added that to their version of this post, and now it's in your notifications.

Similarly, when servers block each other, they're really just no longer updating their version of a thread with content from people on Blocked Server. They can still comment as well as any third party can. You can still comment. But neither of you will see each other. You were technically never even in the same thread to begin with. It was a copy handed out to both of you, and now their copy's had your name deleted.

It takes some mental yoga and for me actual crayons for someone non-tech inclined to get their head around it when every site has always been cordoned off from everywhere else, but the idea is more like...having one of Reddit's many defunct apps, that you just happen to have to sign up for.

You could use Apollo and I could use Boost, and those were different things with slightly different interfaces and user capabilities, but both of us would have been using them to access reddit and talk to one another. I didn't have to download Baconreader to see and interact with people using that. It would have been miserable if that were the case.

As long as my server is able to find a community in order to subscribe to it, or properly sends and receives information, I get the exact same content you get. Which inherently means I can also pick up and move anywhere else if I stop liking my specific server, and at the very worst I'd just have to spend several minutes re-subbing everywhere.

This isn't to say there are never issues with jank between servers, to be candid. There always will be a few, I think:

• Servers have to be informed that others even exist before they'll start pulling content from there, so they can be a bit sparse when they're just starting out.

Meaning there's this catch-22 where Lemmy.world has been repeatedly breaking under the continual weight of hundreds of thousands of users for months, but rectifying it by joining a very tiny one can be utter tumbleweeds. Discovery strikes me as one of the bigger drawbacks to the fediverse as a whole.

• Here and there an image post has rarely come through from another server without the actual image attached to it, or a post simply won't federate to my server for no particular reason. The Baldur Gate 3 community is particularly making me sad atm now that I've realized there are more posts on the community's home server than the ones that I'm seeing.

I'm not gonna act like there wouldn't ever be some of that going on that you might experience if you moved somewhere unlucky, and it could be sensible to compare the feeds of your favorite subs from different servers to see if the content on each is identical. But I'd bet you already are experiencing a bit of it and just haven't realized you missed anything.

Really, the FOMO is negligible for me and pretty easily something you live with. Certainly when the other option is to make 15 different accounts to access the exact same place, for fear of not seeing three whole posts.