git has been using a blockchain for the last 12 years, since long before Bitcoin: Each commit includes the hash of its parent commit. These commits form a chain. Changing the contents of any past commit would break the chain. Each user of the repository keeps a copy of the blockchain on their PC, and they can fetch new "blocks" from any other peer with `git fetch` or `git pull`. The consensus model is based on human…
It's not the best nomenclature in the world, but that's just what it has come to mean.
[1] https://en.wikipedia.org/wiki/Blockchain [2] https://trends.google.com/trends/explore?date=all&q=blockcha...