If you're curious about atproto and feel like a n00b about it, this is a great place to start.

Semi related post on why the moderation of federated Mastodon instances is a problem: https://blog.raed.dev/posts/mastodon_moderation

I wonder why were relays mentioned only mentioned in passing and there was no elaboration on how they interact with the rest of the network. Maybe because doing that would show that there are in fact "instances" in atproto, but who knows?