Blockchain: A definition
A blockchain is a digital ledger of transactions maintained by a network of computers in a way that makes it difficult to hack or alter. The technology offers a secure way for individuals to deal directly with each other, without an intermediary like a government, bank or other third party.
A list of records, called blocks, is linked together using cryptography. Each transaction is independently verified by peer-to-peer computer networks, time-stamped and added to the ledger. Once recorded, the data cannot easily be altered.
While popularized with the growing use of Bitcoin, Ethereum and other cryptocurrencies, blockchain technology has promising applications for legal contracts, property sales, medical records and any other industry that needs to authorize and record a series of actions or transactions.