When you fart and they piss and then someone else flushes the toilet regardless if you were finished.

Everyone is part of the server they signed up with. Federation allows everyone to see each other's posts, filtered through your own server.

If another server defederates yours, their users essentially can't see your (new) comments/posts. But you can see most of theirs.

It is not necessarily a 2 way street. Continuing the example, your server can choose whether or not to defederate back. If it does defederate, you'll no longer see any new comments/posts from the other server.

A much better, longer post about this can be seen here.

And another one here

It is when you throw a person through a window. I think it has to be deliberate, like, you can't accidentally fall out a window and be defenestrated.

the Hexbear.net instance got defederated alot recently, I guess that caused a commotion or some sort of hullaballoo.

This is more of a support question, related to using Lemmy. Please see the sidebar for a list of communities that offer support. Removing under rule #3.