Are you referring to the “notaries” mentioned in the article @jamesray1 cited? I would just point out that this article is nearly 3 years old now and the approach has evolved since then.
The way holo fuel is designed now, all participants in the network act as notaries. There is no centralized coordinator. For every transaction, a random set of validator devices is recruited to perform validation, randomness being based on the similarity of their public key hashes to the hash of the data being shared.
The framework itself does not specify how each app should address potential collisions in the DHT. App developers will need to decide that for themselves. In the twitter example you gave, if a collision is detected, say, if two users choose the same handle at the same time (i.e., before either user’s choice has fully propagated in the DHT), you could code it so the name goes up for auction to the highest bidder, or a message is sent to both users with a release code and they can discuss who wants it more and activate the release code for the other, or if you have a reputation currency, you could give it to the one with higher reputation, or take the median timestamp from the network validations (kind of like how Hashgraph works) and give it to the “first” person to choose the handle by that metric, or etc. etc. Part of the point is to NOT dictate a one-size-fits all consensus mechanism for every situation, but to allow it to be flexible. (I got these examples from listening to this interview with Arthur Brock)
Those boxes aren’t “coordinator” boxes. I think you’re (understandably) confusing Holochain and Holo, which are two different (but related) things.
Yeah, HOT is not Holochain’s “native” currency. Holochain itself is just a free, open-source framework for building distributed applications, which do not necessarily require any kind of currency to function. HOT was the fundraising token for Holo, the distributed web-hosting application built on Holochain, which will be redeemed 1:1 for the mutual credit currency, Holo fuel, when Holo launches.
Full disclosure, I’ve been volunteering in the Holo/Holochain community for about a year, and am new to this forum (just found this discussion trawling the web).