A simple introduction to the Fediverse | Alex
https://alexsirac.com/intro-fediverse/
Alex goes from Twitter to Mastodon, then explains how Mastodon is part of a nebula of platforms called the Fediverse, in a very simple way.
This was originally built to explain Meta's P92 to some people, and I slightly edited it to make it a bit more general. It starts with Twitter, then Mastodon, then the Fediverse as a whole in what I hope is an intuitive manner, and requires no "tech literacy" outside of knowing what Twitter and Facebook are like.