Node

Cryptocurrency nodes are computers or devices connected to a blockchain network that help validate and propagate transactions and blocks. Nodes work collectively to maintain the integrity and security of the blockchain by independently verifying that all transactions follow the network's rules before accepting and passing them along. A full node downloads and stores a complete copy of the blockchain, allowing it to verify any transaction without trusting a third party — this is the foundation of blockchain's trustless design.

There are several types of nodes that serve different roles. Full nodes store the entire transaction history and enforce consensus rules, making them the backbone of network security. Light nodes, also called SPV (Simplified Payment Verification) nodes, only download block headers and rely on full nodes for transaction verification — they are used in mobile wallets where storage and bandwidth are limited. Mining nodes are full nodes that also participate in the process of creating new blocks. Validator nodes in proof-of-stake networks are responsible for proposing and attesting to new blocks, similar in function to miners in proof-of-work systems.

Running a full node is a way for participants to contribute to and independently verify the blockchain without relying on a trusted third party. For traders and developers, understanding nodes is important for building applications that interact with blockchains, assessing network health, or evaluating the degree of decentralization of a given project. A highly distributed network with thousands of independently operated nodes is generally considered more resilient and censorship-resistant than one concentrated in a few large data centers.