Overview
Direct Answer
A node is an individual computer or server that participates in a blockchain network by maintaining a complete or partial copy of the distributed ledger and executing the network's consensus protocol. Nodes form the decentralised infrastructure that eliminates dependency on a single authoritative database.
How It Works
Each node independently receives, validates, and stores transactions according to the network's rules. Nodes communicate peer-to-peer to synchronise ledger state, relay transactions to the mempool, and collaboratively reach agreement on which transactions are valid through consensus mechanisms such as proof-of-work or proof-of-stake. Full nodes retain the entire transaction history; light nodes store only headers and query full nodes for transaction data when required.
Why It Matters
Nodes enable true decentralisation by distributing trust across multiple independent participants rather than centralised intermediaries, reducing single points of failure and censorship risk. The number and geographic distribution of nodes directly influence network resilience, transaction security, and regulatory acceptance in enterprise deployments.
Common Applications
Financial institutions run nodes to settle cross-border payments and securities transactions without intermediaries. Supply chain organisations operate nodes within permissioned blockchain networks to track provenance of goods. Cryptocurrency exchanges and custodians maintain nodes to independently validate transaction authenticity.
Key Considerations
Operating a node requires substantial computational resources, storage capacity, and network bandwidth, presenting barriers to participation for smaller organisations. Node operators bear responsibility for maintaining software updates and managing security vulnerabilities to prevent compromised consensus participation.
Cross-References(1)
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Other entries in the wiki whose definition references Node — useful for understanding how this concept connects across Blockchain & DLT and adjacent domains.
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