For the new guys here, I can explain Mastodon.

Mastodon is a high school where the nerds, the sports guys, the mean girls, the popular students and the teachers are all speaking with each other.

The Federated timeline is like the cafeteria, where everyone talks together.

The Local timeline is the toilet rooms, where the members of a group talk to each other in the same group.

And the Fediverse is an ensemble of independently hosted servers that use web publishing protocols in order to communicate between each other by using decentralized methods of communication.

Easy to understand 🤷‍♂️

#joke