Why is Git not considered a “block chain”?

Question

Git\'s internal data structure is a tree of data objects, wherein each objects only points to its predecessor. Each data block is hashed. Modifying (bit error or attack) an

Answer 1

Well the data structure is similar, if you take the name literally then a git repo would be a "commit chain" and if you consider a commit to be a block then yeah, it's a blockchain.

So it's a pretty good question. The difference here though, is that when we refer to "blockchains" we don't refer only to a literal chain of blocks, but also to consensus algorithms like PoW or PoS allowing peers to verify blocks synchronously.

Git does have the same data structure, but it's not decentralized in the same way. Multiple people can obtain a copy of the entire history of a git repo, but it's not trustless since this source itself is centralized (GitHub, GitLab, GitBucked...). You won't be grabbing of few files from one peer, and other files from another. You will pull all files from one trusted source.

You could implement a chain of blocks with a simple linked list. It wouldn't be a "blockchain" per se until you develop an entire decentralized network around it to ensure the legitimacy of what's written on it.

Simply put, git decentralizes the storage (in a way but it's not really any different than people downloading anything from any server) but it does not decentralize computational operations whatsoever. Here is your difference, on git the consensus is made manually through PRs and peer reviews, but in blockchains, it is fully automated.