Blockchain is a shared, immutable ledger that facilitates the process of recording transactions and tracking assets in a business network. An asset can be tangible (a house, car, cash, land) or intangible (intellectual property, patents, copyrights, branding). Virtually anything of value can be tracked and traded on a blockchain network, reducing risk and cutting costs for all involved.
Key Elements of blockchain are distributed ledger technology, immutable records and smart contracts. As each transaction occurs, it is recorded as a “block” of data. Each block is connected to the ones before and after it, and transactions are blocked together in an irreversible chain: a blockchain.
~ From Blockchain Overview IBM.com
In addition to creating cryptocurrencies, blockchains are being (or could be) used for a variety of systems that require decentralized operation and verification. For example, in a voting system, a blockchain could prevent an attempt by a person to vote more than once, while maintaining an always auditable record. Blockchain ledgers can also be used for tracking valuable assets in order to prevent loss or diversion by criminals. Other systems such as banking, stock trading, and trust and reputation services might be made better integrated, more tamper-resistant and reliable.
~ Graphic from www.blockgeeks.com