Node
Also called: full node · blockchain node
Definition
A node is a computer running a blockchain's software that stores, checks and relays transactions and blocks, helping keep the network decentralized and honest.
How node works
A blockchain has no central server. Instead, thousands of nodes each keep a copy of the ledger and follow the same rules. When a new transaction or block arrives, every node independently checks that it is valid before passing it on. Invalid data is rejected, no matter who sent it.
There are several types. A full node downloads and verifies the entire chain. An archive node also keeps every historical state, which apps and explorers need. A light node keeps only small parts and relies on full nodes for the rest. Mining nodes on proof-of-work chains and validator nodes on proof-of-stake chains also propose or attest to new blocks.
Running your own Bitcoin or Ethereum node lets you verify your transactions without trusting a third party and adds to network resilience. It needs storage, bandwidth and some maintenance. Most wallets connect to public nodes run by providers, which is convenient but means you trust their data and they can see your queries.
Example
Suppose you run a Bitcoin full node at home. A block arrives claiming a miner reward of 6.25 BTC, but under current rules after the April 2024 halving the subsidy is 3.125 BTC plus fees. If fees in that block total 0.2 BTC, the maximum allowed reward is 3.325 BTC. Your node sees the 6.25 BTC claim exceeds that limit by 2.925 BTC, rejects the block and does not relay it, even if the miner is large.
Common mistakes
- Thinking a node and a validator are always the same; many nodes only verify and relay.
- Assuming a wallet app runs its own node when it actually relies on a provider.
- Expecting to earn rewards just by running a regular full node.
Learn and practise
FAQ
Do you get paid for running a Bitcoin node?
No, a regular Bitcoin full node earns nothing directly. People run nodes to verify transactions themselves and support the network. Miners earn rewards, but that is a separate role.
What is the difference between a node and a validator?
A node stores and checks blockchain data. A validator is a node on a proof-of-stake chain that has staked coins and takes part in proposing and attesting blocks.