Blockchain Infrastructure

What is a node in a blockchain?

A node is a computer running a blockchain's software that stores a copy of the ledger and relays transactions and blocks across the network. Nodes check that incoming data follows the network's rules, which is how a decentralized system stays consistent without a central authority. Some nodes, called full nodes, keep the entire transaction history, while lighter nodes store only part of it. For example, thousands of independent nodes each holding Ethereum's ledger make it hard for any single party to alter records. The more widely distributed the nodes, the more resilient and decentralized the network.