What is a Blockchain?

The blockchain is an unquestionably astute development – the brainchild of an individual or a team of individuals known by the handle 'Satoshi Nakamoto'. However, from that point forward, it has developed into something more noteworthy and historic. A blockchain is essentially a database which is comprised of a series (or a 'chain') of transaction groups (or 'blocks'). Each block can have multiple transactions in it and the size of each block can vary. Blocks are verified by independently operated computer networks (known as 'pools') through a process known as 'mining'.

What is Mining?

A Bitcoin miner is essentially a computer workstation dedicated to solving the overly-complex math problems known as 'hashes'. Hashes are used in encrypting the 'blocks' on the blockchain. The whole process relies on economic incentives for miners by rewarding them Bitcoin for every block they validate successfully. When a block is validated it gets added to the chain and the other miners download it to their copies of the blockchain for use in validation of future blocks.

What is Bitcoin?

Bitcoin is the world's first peer-to-peer electronic money also known as a 'blockchain'. Bitcoin is essentially a protocol. The original Bitcoin protocol was first outlined in Satoshi Nakamoto's Bitcoin Whitepaper. Some time after Bitcoin's birth or the 'Genesis Block', the communication channels of it's creator, Satoshi, went dark. Left in the hands of a team of developers known as 'Bitcoin Core', the original Bitcoin blockchain has been changed (or as they say "upgraded") several times in several crucial ways. This also resulted in the birth of many other projects (such as Ethereum and it's dApp platform) that attempted to do what Bitcoin could have done from the very start (as per the whitepaper). Since then, Bitcoin itself underwent several soft and hard 'forks'.

What is a Fork?

A fork is essentially a split in versions of the blockchain protocol that miners run on the network. This can happen when there is a disagreement about upgrades and only half of the miners want to implement a proposed set changes, while the other half of the mining network do not. A classic example of the whitepaper's "Nakamoto Consensus" principle at work. 

These splits can cause different versions of the blockchain to exist. Forks can also be induced maliciously through attacks such as the 51% attack. An attacker with enough hashing power (or computers to mine with) can control more than 51% of the network and essentially in laymen's terms temporarily create their own rules and potentially causing a fork. This also creates an exploit called 'Double Spending'. In summation, there are several way in which forks can happen but hopefully you now have a better understanding of what a 'fork' is.

Has Bitcoin Ever Forked?

Yes. Let me give you a brief history. They say a picture is worth a thousand words, so quickly I made up this diagram to show you all the soft and hard forks that took place with the Bitcoin blockchain since it's first ever block (or Genesis block).

Genesis Block: This is where it all started. The first ever block is mined.

Bitcoin Cash: Forked at block 478558, 1 August 2017, for each bitcoin (BTC), an owner got 1 Bitcoin Cash (BCH).

SegWit: Short for 'Segregated Witness' A soft-fork implementation of a protocol change.

Bitcoin Gold: Forked at block 491407, 24 October 2017, for each BTC, an owner got 1 Bitcoin Gold (BTG). This is what is often referred to as a 'Shitcoin'. Ironically, not everything with the name Bitcoin in it is gold.

SegWit2x: On 21 July 2017 Bitcoin miners locked-in a software upgrade referred to as Bitcoin Improvement Proposal (BIP) 91, meaning that the Segregated Witness upgrade activated at block 477,120.

Bitcoin SV: Forked at block 556766, 15 November 2018, for each Bitcoin Cash (BCH), an owner got 1 Bitcoin SV (BSV). This is my favorite blockchain right now because this fork restored the original whitepaper protocol. Including op codes which will allow for the building of applications on the blockchain.

Lightning Network: This is a side-chain and not a fork. But I've included it anyways because it is an addition to the Bitcoin network that is not part of the original Satoshi whitepaper. It was created to help solve the scaling problem of the SegWit2x Core version of Bitcoin.

The Bitcoin blockchain has sparked many different copies of it's protocol as well, which were implemented in a much worse way. Some of these include Bitcoin Diamond, Bitcoin Candy, Bitcoin Private, SuperBitcoin, Bitcoiin and I could go on all day with these awful copies and cheap clones.

The main projects today, which I dubbed the "Holy Trinity" are the three most popular Bitcoin blockchains competing for supremacy. Starting from the original, they are:

  • Bitcoin Core (BTC)
  • Bitcoin Cash (BCH)
  • Bitcoin SV (BSV)

The ONLY implementation that follows Satoshi Nakamoto's original vision for Bitcoin, is BitcoinSV, which forked from the BitcoinCash chain at the end of 2018.

Here is one of the best presentations by Satoshi himself, also known as Dr.Craig S. Wright, the Chief Scientist at nChain.