A blockchain is a shared digital ledger that records transactions in linked blocks. Each block contains data, a timestamp, and a reference to the previous block.
Verification and security
Networks use consensus mechanisms to agree on which transactions are valid. Cryptographic links make unauthorized changes difficult because altering one block would require changing later records across the network.
Beyond cryptocurrency
Blockchains can support applications involving records, ownership, identity, and automated agreements. Their usefulness depends on careful design, reliable data, and responsible governance.
