What Is a Node?

A node is a computer running software that keeps a copy of a decentralized network's transaction records, checks new transactions against the network's rules, and passes valid ones along to other nodes.

What checking a transaction involves

When a node receives a transaction, it doesn't just forward it blindly. It confirms the signature matches the claimed sender, checks that the funds being moved actually exist at that address, and verifies the transaction follows the network's formatting rules. Only transactions that pass every check get relayed onward. A node that received an invalid transaction simply drops it — there's no appeal process, because the rules are fixed and identical for every node running the same software.

Relaying versus block production

Most nodes spend their time validating and relaying — passing checked transactions to their peers so the whole network stays in sync. Producing new blocks is a separate, specialized role that only some participants take on, using the transactions that nodes have already validated and propagated. A node doesn't need to produce blocks to serve a useful function in the network.

Using a network versus operating part of it

Most people interact with a decentralized network through a wallet that connects to someone else's node, which is enough to send and receive digital assets. Running your own node instead means your own computer independently verifies every rule for itself rather than trusting another party's account of the record. Both approaches work; they differ in who is doing the checking on your behalf.

For how this fits into the wider network of computers and software involved in self-custody, see Ecosystem, and for tools that let you observe network activity directly, see Network Monitor.