If you want to see what's changed, the last couple of major version release notes are helpful.
(v2.6.1 is just a quick bugfix)
Federation relays are explained in the 2.5 notes. Effectively you can merge the local timelines of two or more instances. Nice if you want your instance's conversation to feel a bit bigger.
I'm very interested to know how ausglam.space residents feel about this. We have a standing offer from aus.social to federate if we want to.
Link ownership verification is explained in 'Edit Profile'. Basically you link to your mastodon account from your website and include a relationship marker of 'rel="me" '. The metadata fields in Mastodon automatically includes 'rel="me"' so you have established that the same person controls both properties. You can see what it looks like on my profile page:
@hugh This decision is made at the admin level, no? So individual users can't choose to have their local timelines either be actually local or be inclusive of other instances...
I'm not a big user of the local timeline stream anyway bc 95% of my toots are follower-only so it wouldn't impact me too much, but I guess I'm uneasy just bc I'm a toot recluse, and people who use masto to actually talk to and meet people may feel differently
@hugh aus.social seem like a friendly pack of galahs, so if you decided to federate I'd be fine with it
@alissa actually I just realised I may have misunderstood how it works. It may only pull them into the federated timeline, which seems like it has minimal downside other than making the DB a bit bigger. I'm investigating...
@hugh oh well I almost never delve into the fediverse so this impacts me even less. I'd be happy with whatever you choose to do
@alissa yep confirmed: it’s like when someone follows someone on another instance, except I just subscribe to everyone on the whole instance: pulls it into Federated.
@hugh that doesn’t seem too bad, I’d be fine with that
@alissa yeah i’m going to do it. Once I figure out how LOL. I think it’s a bit like following an RSS feed.