Just joined Lemmy today. From what I understand, there are different Lemmy instances that host different communities. I supposed that to interact in a community hosted in a certain instance, I would need to create an account for that instance. Ended up creating 10 different accounts.
I've also found it useful to have multiple to compartmentalize the subjects I subscribe to on each and limit what I see when I am in different "modes".
Makes it easier to see was is active in communities local to that specific instance too.