Blockchain's record data - in blocks - and securely store this data by chaining those blocks together using cryptography, hence a block-chain.
Satoshi Nakamoto - the alias of the individual or group behind Bitcoin - conceptualised the idea of a blockchain in a 2008 Whitepaper (blueprint). The ability to create a decentralised ledger of transactions was fundamental to the viability of Bitcoin - a new peer-to-peer digital cash - and solving the double-spend problem.
In other words, how to create a purely digital money that cannot be spent twice and doesn’t go through a financial institution; it just flows from person-to-person across a distributed network.
The blockchain was a central element in Satoshi's solution, in combination with a method for ensuring that only valid transactional data was added to each new block - known as the consensus mechanism.
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