What is the Fediverse? What is not the Fediverse?

I think I made a similar #poll before, but I'd like to ask again:

What do you not consider part of the Fediverse?

Please answer the poll in this post and the 3 polls in the replies.

• only Mastodon is the Fediverse (3%, 1 Stimme)
• only my instance is the Fediverse (6%, 2 Stimmen)
• I don't know the Fediverse (3%, 1 Stimme)
• I will answer the polls below (87%, 28 Stimmen)