Eugen RochkoHm, I actually don't know if there's a word for it, but I was talking about blockchains with someone, and one of my points is that the blockchain is decentralized, but also kind of isn't, in the sense that there is only one ledger that everyone shares. This as a counterpoint to a federated system like Mastodon, where every server can exist independently of others. Is there a word for this?
Actually maybe my issue is that I consider "distributed" to be a subset of "decentralized", when maybe they are separate properties, in which case you could say the blockchain is distributed but centralized..?
Lord Guysbert de Fieri 
@Gargron Ah! I would say it is the reverse: decentralized is a subset of distributed.
watchtheriver@Gargron The term decentralized is used for block chains because while there is consensus there is no single centralized authority and the system falls down without distributed consensus and potentially suffers when compute power of the system is too centralized, with distributed systems like federated chat , there may not be strict ordering across all systems, there are usually central authorities, perhaps ( likely ) sharded ( using distributed stores like couchbase or memcache + persistence
@Not sure the #blockchain necessarily is (must be?) centralised in all possible implementations.
Strypey@ZeniorXV @Gargron side note; can we all please get into the habit of saying #blockchains, not "the blockchain"? The latter can tend to confuse newbies into thinking there's only one blockchain, and that all blockchain startups are using it, the same way there's only one internet, and all internet startups are using it.
Yuval Marcus@Gargron Wait, are you saying that a blockchain is centralized because there is only one ledger? How is that centralized? There is not one authority that can append to the blockchain. The blockchain is supposed to be the same ledger shared across many machines. We say that cryptocurrencies are decentralized because in theory there is not one central authority that "mines" and secures the network (that anyone can join and help mine)--of course this is not fully accurate: http://hackingdistributed.com/2018/01/15/decentralization-bitcoin-ethereum/
@Gargron I may have found an answer to the dilemma. We can say that Bitcoin and similar cryptocurrencies are decentralized but that they're conceptually centralized around a global singleton. Ie. the concept of a Blockchain. So the system is decentralized in that not one person controls authority but it's centralized around a common concept (the global singleton). This makes sense for the purpose of Bitcoin but maybe not for social networks.
See Network Topology section: https://www.scuttlebutt.nz/concepts/
Edward L Platt@Gargron Your usage is consistent with Paul Baran's original descriptions of "decentralized" and "distributed".
What you're getting at is that the system for maintaining the ledger is decentralized, while the system for interpreting the ledger (associating a token with a public key) is centralized.
chromakey@Gargron that's accurate. Blockchains are decentralized in that there's a single source of truth, but distributed in the sense that the source lives in many places
@Gargron sorry that should say centralized
SunDancer@Gargron
Blockchains are cloned maybe?
Blockchains are cloned maybe?
maho@Gargron Wouldn't "centralized" imply that there is one single point of failure which can be taken out? How does a (healthy) blockchain fit that description?