BlockChains are a logical next step beyond centralised and distributed (networked) ledgers used to record all forms of transaction, files and documentation for legal, medical, industrial, government and defence entities. The biggest change is the lack of any middle man and/or institutions. With open and available to anyone, individuals and groups as well as companies can build open, closed, public or private BlockChains.
The technology constitutes a step function in security, privacy, reliability and utility. Although it is the basis of BitCoin and other currencies, it is not limited to financial transactions and can be applied to all forms of asset movement, agreements, documents, files, voting and more across all sectors.
The base concepts are founded on networking and distributed adjudication processes that generally embrace Digital Signatures, Public and Private Key, Encryption, and Hash Checks.