Bitcoin node

A Bitcoin node is software that speaks Bitcoin's peer-to-peer protocol. It connects to other nodes, downloads blocks and transactions, checks them against the rules, and keeps track of the current chain state.

In practice, people usually mean a full node: software that independently verifies every block and transaction instead of trusting a third-party server. Running one is how a user checks Bitcoin's rules for themselves, including the supply limit, script validity, and whether a payment really confirmed.

Nodes can be packaged in different ways. Some are general-purpose implementations like Bitcoin Core. Some are lightweight or specialized designs such as Floresta. Some are pruned, which means they discard old block data after validation to save disk space. Pruned nodes are still full nodes because they still verify the chain themselves.

Wallets, Lightning apps, block explorers, mining software, and other services often depend on a node for trustworthy chain data and transaction broadcast. Without enough people running their own nodes, more users end up relying on centralized infrastructure to tell them what Bitcoin says.

References

• Running a full node
• Bitcoin Core validation
• bitcoin/bitcoin