Okay before I start adding in earnest, a Mastodon primer.
HOME: These are the people you follow across any instance.
LOCAL: These are just the members of the nineties.cafe instance.
FEDERATED: As you follow people, they are discovered and added to our federated timeline. Friends of friends of friends, etc.
The social network of the future: No ads, no corporate surveillance, ethical design, and decentralization! Own your data with Mastodon!