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 have two because Jerboa's "switch account" feature pretty much enticed me to make another account on programming.dev so I could more easily browse that instance's communities.
I hope Lemmy implements more cross-instance features, like being able to browse communities by their parent instance.