Since each block contains information about the previous block, they effectively form a chain (compare linked list data structure), with each additional block linking to the ones before it. Each block contains a cryptographic hash of the previous block, a timestamp, and transaction data (generally represented as a Merkle tree, where data nodes are represented by leaves). For other uses, see Block chain (disambiguation).Ī blockchain is a distributed ledger with growing lists of records ( blocks) that are securely linked together via cryptographic hashes.
