"Blockchain, generally, is a database technology that records and stores information in blocks of
data that are linked, or “chained,” together. Data stored on a blockchain are continually shared,
replicated, and synchronized across the nodes in a network—individual computer systems or
specialized hardware that communicate with each other and store and process information. This
system enables tamper-resistant record keeping without a centralized authority or intermediary.
There are multiple types of blockchains, and, depending on the type, recorded data may be
accessible to all users or only a designated subset. All blockchains share common characteristics,
including decentralization (i.e., no centralized authority), immutability (i.e., the blockchain records are unalterable), and
pseudonymity (i.e., how users’ real-world identities are handled). Certain blockchain types may offer greater levels of
decentralization and pseudonymity than others. New blockchain applications, such as smart contracts, non-fungible tokens,
and decentralization autonomous organizations, may automate processes or replace intermediaries in a variety of fields.
Recent developments in blockchain governance protocols and consensus mechanisms have raised concerns about the
environmental impact, oversight, and accountability of blockchain networks.
Since its creation in 2008, blockchain has been most commonly associated with cryptocurrencies—digital currencies that
users exchange through decentralized computer networks. More recently, public and private sector actors have used
blockchain applications in fields such as supply chain management, identity management, and asset registration. Blockchain
technologies may enable establishing the provenance of goods and tracking their progression through a supply chain;
identity-management with digital credentials; recording the ownership of digital and physical objects; and the transfer of
property, rights, or goods without a third-party intermediary. The United States is a hub for private-sector blockchain
development, and many states and federal agencies are experimenting with novel blockchain provenance applications,
including the Food and Drug Administration and Department of Treasury..."
Blockchain
