A blockchain is a public digital ledger of transactions that records information in a way that makes it difficult to hack or alter. The technology allows a secure way for individuals to deal directly with each other, without an intermediary like a government, bank or other third party.
The growing 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 a growing chain of data. Once recorded, the data cannot 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.