What Is a Blockchain Node?
A node is a computer that connects to a blockchain network and runs its software. Nodes keep a copy of the chain, check new transactions and blocks against the network’s rules and share them with other nodes.
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A node is a computer that connects to a blockchain network and runs the network’s software. Nodes keep a copy of the chain, check new transactions and blocks against the network’s rules and pass that information on to other nodes. A blockchain’s decentralization rests largely on these independent nodes spread around the world.
What does a node do?
- Validation: it checks every incoming transaction and block against the rules and rejects anything invalid.
- Record-keeping: it stores the chain’s history and updates it as new blocks arrive.
- Relaying: it forwards valid transactions and blocks to other nodes on the network.
Thanks to nodes, users can verify transactions for themselves without trusting a company or intermediary.
Types of nodes
Full node: downloads the chain’s entire history and independently checks every rule. A computer running Bitcoin Core is a full node.
Pruned node: verifies every block but deletes older block data to save disk space.
Light node (SPV): doesn’t download the full chain; it verifies only block headers and the transactions relevant to it. Most mobile wallets work this way.
Archive node: on networks such as Ethereum, a large node that keeps every historical state, mainly used by data services.
Node vs miner vs validator
Every node enforces the rules, but it doesn’t have to produce blocks. On proof-of-work networks, blocks are produced by miners; on proof-of-stake networks, by validators. Miners and validators run nodes too, but not everyone running a node produces blocks. On Bitcoin, full nodes reject an invalid block no matter how much hash power went into producing it.
Should you run your own node?
Running your own full node lets you verify your transactions without relying on someone else’s server, and it improves your privacy. A Bitcoin node needs enough disk space (several hundred gigabytes), a reliable internet connection and some basic technical knowledge. There’s no reward; the motivation is security, privacy and contributing to the network.
Running a node doesn’t by itself keep your funds safe; storing your private keys securely matters just as much. For the bigger picture, see our blockchain guide.
Why does the number of nodes matter?
The more independent nodes there are, the harder it becomes to control the network or change its rules unilaterally. Even if a group of miners or validators tried to produce blocks that break the rules, the many nodes enforcing those rules would reject them. That’s why it matters for a network’s resilience that nodes are spread across different countries, internet providers and operators.
Nodes and network upgrades
During protocol upgrades, the software version nodes are running is decisive. With a soft fork, older nodes can keep following the network. With a hard fork, nodes that don’t update split off from the rest of the network. Node operators therefore need to follow upgrade announcements through official channels.
Frequently asked questions
Can you earn money by running a node? Running a Bitcoin full node pays no direct reward. Rewards go to miners who produce blocks and, on proof-of-stake networks, to validators.
Is my mobile wallet a node? Most mobile wallets aren’t full nodes; they check transactions through other servers or lightweight verification methods. That’s convenient, but it isn’t as strong as a full node for privacy and independence.