Blockchain

A blockchain is a distributed ledger made of a growing list of records, called blocks, that are securely linked together through cryptographic hashes. Each block carries a cryptographic hash of the block before it, a timestamp and transaction data, so the blocks form a chain in which each new block links to the ones that came before it. Because altering any recorded block would also require altering every subsequent block and obtaining network consensus to accept the change, blockchain transactions are resistant to retroactive alteration. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/