Gregory's Server
Doesn't the video start off on the wrong foot by saying "Mastodon is a Technology" when anyone with a browser can quickly find Mastodon gGmbH?
It goes on to explain, showing the common #fediverse logo-diagram and then explains #ActivityPub, while calling it Mastodon. I confess I stopped watching at that point.
"Mastodon" is not "like email", it is like Hotmail, or Outlook, or Gmail, a wrapper app for the #W3C #ActivityPub standard protocol, and ActivityPub IS very much like email 😏