Node
A computer running a blockchain's software, keeping a copy of the ledger and relaying transactions to peers.
A node is any machine that participates in a blockchain network. Full nodes store the entire history and independently check that every block and transaction follows the rules. If a block breaks the rules, a node rejects it, no matter who sent it.
More independent nodes means more decentralization and harder censorship. Anyone can run one; Bitcoin and Ethereum both have tens of thousands spread worldwide. Running your own is the surest way to verify the chain yourself.
Related terms
A shared digital ledger that records transactions in linked batches, copied across many computers and hard to alter.
ValidatorA participant in a proof-of-stake network that proposes and confirms blocks, putting staked coins at risk for honesty.
DecentralizationSpreading control and data across many independent participants so no single party can dictate or shut things down.
MinerA participant who spends computing power to solve proof-of-work puzzles and earn the right to add a block.