I am new and trying to understand how Lemmy works. I am posting this from my lemmy.world account, on a lemmy.ml community. It seems like you can read, post, subscribe to whatever community outside of the instance you’re registered with. So… Why register on lemmy.world vs lemmy.ml or any other instance, if all communities are accessible to everyone?
You don’t, that’s the beauty of federation, you can pick whichever instance you want and interact with everyone!
The actual reasons to pick an instance are just rules/moderation and ping/bandwidth, really.
Some instances let you create communities, others don’t, for example.