Yup, as said already, exactly like that.
Most social media these days is a single system / platform, like Facebook or Reddit. Federated media is rather like email where whichever service you send it from (Gmail, Hotmail, Yahoo, etc.), the recipient receives it and you don't need to care about exactly how.
I feel that analogy is overly simplistic, and leaves people baffled as to what defederation means. So instead I like the idea that federation is akin to ships (pirate or free trade) passing messages around - some captains have beef with other captains and refuse to talk with them, but otherwise you have access to the entire network of all messages.
It does get slightly more complicated when you rise up above the forum-based "Threadiverse" (Lemmy, PieFed, Mbin, and arguably flarum and nodeBB) to discuss the wider ActivityPub-based "Fediverse" - those entirely different platforms can pass messages between them, but it is not always so easy or straightforward, e.g. Mastodon is based on people whereas the Threadiverse is centered around "communities" (on Reddit these were called subreddits), so for someone on Mastodon to talk to someone on Lemmy (or PieFed) they would have to jump through several hoops to make it happen (although Mbin eases that process). That's basically the end of my knowledge there bc I don't use Mastodon but I hope that helps to have gone that far at least.
Getting back to the ship analogy, you personally could, in theory, have your own ship, which you could use either privately, or share with a few friends, or even open it up to the public. That "machine" that you use, that "server", in Fediverse terminology is called an "instance". And it will have "admins" who run it, as well as "moderators" who run the communities on it. Also, it will need to pick which variety of software to run, so like there are Lemmy instances, and PieFed instances, and Mbin instances, etc. Sometimes the same admins run multiple of them, e.g. lemmy.world is by far the largest Lemmy instance, and now they have branched out to try out a PieFed instance as well called PieFed.world. It's the same people, possibly running on the same machine or at least you could imagine that, but a different software platform.
lemmy.dbzer0.com is a Lemmy instance, and one day that awesome admin dbzer0 (a real person, though surely that's not their irl name😂) may likewise make a PieFed instance, perhaps it will be called PieFed.dbzer0.com, or something, who knows.:-)
Regardless, the messages will get passed between them. Your choice of instance gives you a different experience bc you are picking a different captain of your boat - maybe you'll even decide to become one yourself - and then yes the software that is run on the instance greatly changes your method of access. e.g. PieFed has flairs (both user and post varieties) and polls, but since Lemmy lacks those, the only way to participate in such is to use that same software, i.e. to sign up on an instance that runs it (or maybe one day Lemmy will catch up and offer all 3 of those? I am sure that it will, but I sincerely doubt it will happen anytime "soon"). Here is an example of a post that uses a poll (and hashtags).
Btw the sidebar of that community has some good resources to learn more about the Fediverse if you are interested. But that post itself is not able to be viewed on a Lemmy instance, since it uses a poll which Lemmy does not know how to handle.
And then defederation is a whole other thing. When one captain (admin) gets mad at another captain (admin) for just absolutely REFUSING to respect the rules that collectively were agreed upon - sending spam, harassment of users, trolling behaviors etc. - defederation can be a method of last resort to cut off all communication with them. It stops any messages from that point forward - for good or bad - which can cause confusion but I want to point out that the captain ("admin") is literally the owner of their personal ship (machine/"instance") and so has the right to do as they please with it. And all the more so if the instance is open to the public, in which case they arguably have the responsibility to protect their users from the trolling and harassment campaigns. "Free speech" is never free, someone must always bear the cost, of maintenance, of platforming it, and so on.
Kierunkowy74@piefed.zip 12 hours ago
Exactly like that.
cerebralhawks@lemmy.dbzer0.com 12 hours ago
Thanks! I went and followed the discussion link the other guy posted. I saw one concern — the handling of voting. But someone/some people are going behind a lot of those comments and saying they fixed it based on user feedback. So that’s good. I also feel I understand the two (Lemmy and Piefed) and their relationship a bit more.
If it sounds like I’m a bit eager to learn, it’s because I like to help others, but to do that I have to understand things first.