Blockchain is a distributed ledger that records transactions in cryptographically linked blocks, replicated across a network of nodes so that no single party controls the record. Each block contains a hash of the previous block, creating a tamper-evident chain; consensus mechanisms (proof of work, proof of stake, and variants) determine how new blocks are added. Bitcoin introduced the concept for peer-to-peer currency; Ethereum extended it with smart contracts and decentralised applications. Enterprise implementations, such as IBM Blockchain and Hyperledger, focus on permissioned networks for supply chain, trade finance, and identity.
The technology addresses trust and transparency in systems where intermediaries are costly, opaque, or absent. Use cases span cross-border payments (e.g. Ripple), supply chain traceability, land registries, healthcare data sharing, and intellectual property provenance. Regulators and institutions are exploring central bank digital currencies and tokenised assets that borrow from blockchain design without full decentralisation. The same properties that enable censorship resistance and disintermediation also complicate compliance, reversibility, and governance.
Adoption remains uneven: cryptocurrency markets are volatile and energy-intensive proof-of-work consensus has drawn environmental criticism. Scalability limits have driven layer-two solutions and alternative architectures. Regulatory clarity is still evolving, with jurisdictions differing on classification, custody, and disclosure. For enterprise and public-sector applications, hybrid and permissioned designs are often preferred. As interoperability and standards mature, blockchain and related distributed ledger technologies are likely to persist as one option in the trust infrastructure of finance, logistics, and digital identity.