This question is especially for people who have joined in the last week. Have you used other fediverse platforms or is this your first time really using one? What do you think of it so far? Are you aware that you can comment on Lemmy posts with a Mastodon account?
The difference is only on who runs the instance, and what particular rules said instance has, like restricting submissions, or disabling downvotes or nsfw communities. That’s it. That’s why you can make an account on lemmy but still post and comment and suscribe in kbin communities.
https://join-lemmy.org/instances this is a list of most but not all instances out there.