Simple blockchain

A blockchain is a type of distributed ledger or decentralized database that maintains a continuously growing list of records, called blocks, which are linked and secured using cryptography. Each block typically contains a cryptographic hash of the previous block, a timestamp, and transaction data. By design, blockchains are inherently resistant to modification of the data, and serve as an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable and permanent way.