Overview
A Bitcoin node is any computer running Bitcoin software that connects to the peer-to-peer network. Nodes serve as the backbone of Bitcoin's decentralization by independently validating every transaction and block against the consensus rules. The more nodes operating, the more resilient and decentralized the network becomes.
Types of Nodes
┌──────────────────────────────────────────────────┐
│ Bitcoin Node Types │
├──────────────┬───────────────────────────────────┤
│ Full Node │ Validates everything, stores full │
│ │ blockchain (500+ GB) │
├──────────────┼───────────────────────────────────┤
│ Pruned Node │ Full validation but discards old │
│ │ blocks to save disk space │
├──────────────┼───────────────────────────────────┤
│ Archival Node│ Full node that serves historical │
│ │ blocks to other nodes │
├──────────────┼───────────────────────────────────┤
│ SPV Node │ Light client, trusts miners for │
│ │ validation, verifies headers only │
└──────────────┴───────────────────────────────────┘
What Nodes Do
Every full node performs several critical functions:
- Validates transactions: Checks that signatures are valid, inputs exist and are unspent, amounts balance, and scripts execute correctly
- Validates blocks: Verifies proof of work, block structure, coinbase reward, and all transactions within
- Relays data: Propagates valid transactions and blocks to connected peers
- Enforces consensus: Rejects any block or transaction that violates the protocol rules, regardless of who produced it
Why Running a Node Matters
By running your own node, you verify all rules yourself rather than trusting someone else. Your node ensures that the bitcoin you receive is genuine, that no inflation beyond the 21 million supply cap has occurred, and that all transactions follow the protocol. This is the foundation of Bitcoin's trustless model.
Common Misconceptions
Running a node is not the same as mining. Nodes validate and relay data but do not produce blocks or earn rewards. However, nodes are arguably more important than miners for enforcing the rules — miners propose blocks, but nodes decide whether to accept them.