Bitcoin is the first digital currency based on blockchain. It solved the double-spending problem and enabled peer-to-peer transactions on a large scale. Bitcoin was designed to work as a trustless digital currency that would function without government oversight or a central bank.
Bitcoin was developed by Satoshi Nakamoto, whose identity has never been confirmed and has become the subject of great intrigue. Bitcoin builds upon on other cryptographic and digital currency projects that came before it, but its use of blockchain made it more viable. Nakamoto originally released his white paper and open-source software on a cryptography forum. He mined the first block of the Bitcoin chain, called the genesis block in January 2009.
Bitcoins are created as a reward for a process known as mining. One of the core innovations of Bitcoin, is its consensus algorithm, which creates an incentive system that rewards miners for confirming transactions.
Hal Finney, who developed the first reusable proof-of-work system (RPOW), several years before, was the first Bitcoin adopter and received the first bitcoin transaction ever recorded on its blockchain.

Flash Coin is a cryptocurrency designed to be used for everyday transactions. Flash's blokchain has a delegate-based consensus model that depends on elected delegates to verify transactions. These delegates elect 25 Miners who create new blocks on the blockchain. Each miner is given a specific time where they can mine a block. The Flash Coin algorithm also introduces a concept called Consensus Height, which refers to the moment when more than half of elected miners have created a block on top of another block in the chain.

Bitcoin Cash is a cryptocurrency that was created as a result of a hard fork of the original Bitcoin blockchain that took place in 2017. Due to the open source nature of the Bitcoin protocol, and the lack of a central governing body to resolve disputes, the Bitcoin community became extremely divided about what to do about rising fees and slow transaction times. As the platform's transaction volume increased, and the associated fees to confirm them also increased dramatically, many people began advocating for a larger block size.
In mid 2017, a group of developers introduced segregated witness technology, or SegWit, that was designed to increase Bitcoin's scalability by moving some transaction details off of the blockchain. Segwit was meant to resolve the issues that revolved around the growing amount of transaction data, but many members of the Bitcoin community felt that it undermined the original vision outlined by Satoshi Nakamoto.
On August 1, 2017, they initiated a hard fork of the protocol that created Bitcoin Cash and implemented an increased block size of 8mb. At the time of the fork, bitcoin holders automatically became owners of the same number of Bitcoin Cash units. The increased block size led to faster transaction times and made Bitcoin Cash easier to use as a medium of exchange.