Thomas Lord wrote:
But with the Fediverse you have it,
Not at all - that's a very different system for a fairly
narrow set of purposes, but I'll drop it.
They call the architecture with many servers a federation but
it's the same as the Usenet one, see these images
https://dataswamp.org/~incal/pimgs/comp/net-arch.png
https://dataswamp.org/~incal/pimgs/comp/usenet.png
So while in theory it is total P2P in practice it is
client-server only there are many servers that themselves
share information, or temporarily acts as clients if you will.
It's the old redundance and propagation scheme all over.
So then the Fediverse (a concept) is the whole set based on
this network idea, and the Mastodon "instances" (servers) that
offer a FOSS Facebook/Twitter-ish service is just one service
of many possible, albeit one that has been realized.