Thank you and @samokosik for the explanation. I understand that the underlying communication protocol is the same; what’s not clear to me yet is how I can follow communities from Mastodon or post from there – but of course there are good tutorials out there, just haven’t found the time to go through them yet.
What I don’t get at the moment is how a Lemmy community would look like on Mastodon. Maybe like a hashtag-topic? I agree with others here that the context and way of interacting within a (Lemmy) community is quite different from those of Mastodon exchanges. So I suppose I would be quite confused seeing the two together. Or maybe not – I haven’t checked this, so there’s half a prejudice on my part there.