Blockchain

A blockchain is a type of digital ledger where transactions grouped into blocks are replicated across a network of participants. Blockchains can enable a decentralized ledger system of transactions which does not rely on any central authority or trusted third parties for transaction validation. All participants in the peer-to-peer network are known as nodes, and maintain a full record of all transactions on the blockchain communicating directly following a protocol that forms a distributed consensus on the next valid block in the chain.

Each block in the blockchain contains a timestamp, transactional data, and a cryptographic hash link to the previous block. This creates a time-ordered chain of links from the genesis block to the most recent block that cannot be altered retroactively without alteration of all subsequent blocks, requiring a collusion of a large portion of the network.