Also I'm just going to post this figure again because it was so vital in refining the way I think about network-y things.
"Centralized" is gmail. "Decentralized" is gmail. "Distributed" is IPFS or other P2P protocols.
The thing is, "decentralized" is really easy. Decentralized is 1980's tech. There's no technological reason to not have most things be decentralized.
Distributed is a lot harder. That's still an active research problem for many domains.
@icefox Huh. Whats the central backbone for email, then? The DNS servees, or whatever? :?
@Angle Basically, yes. Look up "MX records". It's how email servers find each other.
DNS is sort of between centralized and decentralized; anyone can run their own DNS server but they need to talk to a registrar to get it connected to the rest of the DNS hierarchy. Most registrars are run as more-or-less-virtuous nonprofits and people get *pissed* when they aren't, so this has mostly worked okay so far.
"Decentralized" is email, rather. Derp.