what is blockchain simple?
<answer> A distributed database that provides an unalterable,public record of digital transactions. <context> It is a ledger, a distributed, digital ledger. A more wordy definition: The blockchain is a distributed database that provides an unalterable, (semi-)public record of digital transactions. Each block aggregates a timestamped batch of transactions to be included in the ledger – or rather, in the blockchain. Each block is identified by a cryptographic signature.