Why don t we consider Git as a Blockchain

Question

The following extract is the understanding I have of Git :

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 intermediate block will be noticed when the saved hash und the actual hash deviate.

My question now is - How is this concept different from block chain?

Answer 1

There are quite a few reasons for it -

In a blockchain implementation, every block is verified independently multiple times before it is added to the blockchain. On the other hand, many git projects do not require independent verification and, when they do, they only require one person to sign off on a change before it is committed to the repository. Hence, with at most one point of validation that you must trust, git breaks one of the core tenets of blockchain technology.

Secondly, git history can be re-written which negates a very important concept of Blockchain i.e. the immutability of the ledgers.

Thirdly, A git repository is not necessarily duplicated on many servers. You can work from a gitrepository locally and if your local disk were corrupted, you would lose everything. Blockchain technology implies the reproduction of the ledger across servers.

Also,

Blockchain is unlike Git in a way that everyone strives to work on a single branch. In Git everyone may have several branches and fork and merge them all day long. In Blockchain one cannot “merge” forks. Blockchain is a actually a tree of transaction histories, but there is always one biggest branch and some accidental mini-branches that have no value at all. In Git content matters (regardless of the branch), in Bitcoin consensus matters (regardless of the content).

Answer 2

Cyber Currencies like Bitcoin, use a distributed consensuses cryptographic chain of blocks (merkle tree). Common usage has shortened this to 'blockchain'

While git uses a chain of blocks (merkle tree), it lacks the distributed consensuses cryptographic components that common usage of the term 'BlockChain' imply.

Answer 3

Blockchain is not just any chain of any blocks.

Blockchain is when there is a way of determining the main chain when two or more are diverted, and when no central authority is needed for that determination.