Node

Key points

• A node is a computer that participates in a blockchain network, communicating with others to validate and propagate transactions and blocks.
• Each node keeps a copy of the ledger and independently verifies whether the protocol's rules were followed, without relying on a coordinator.
• It is the distribution of thousands of nodes that gives the network resilience and censorship resistance, since there is no single point of control.

What is a node?

A node is any participant in a blockchain network that connects to others to keep the system running. It receives transactions, checks whether they are valid according to the protocol's rules, and forwards them onward. By running a node, a person or company starts validating the network on their own, without needing to trust what third parties say about the state of the ledger.

How it works

When a user sends a transaction, it spreads from node to node until it reaches the entire network. Each node independently checks whether the transaction obeys the rules, for example whether the sender has sufficient balance and whether the signature is valid. Invalid transactions and blocks are discarded, which prevents incorrect data from propagating.

There are different types of nodes. A full node keeps and validates the entire history, offering the highest level of independent verification. Others store only part of the data to save resources, relying on full nodes for certain checks. In mining or validation networks, some nodes also take part in creating new blocks.

The more full nodes there are, distributed among different operators and regions, the harder it becomes to manipulate or shut down the network, which strengthens its security.

Why it matters

Nodes are the infrastructure that underpins decentralization. For a company integrating on-chain payments, running or accessing trustworthy nodes is what guarantees reading the blockchain's state without depending on an intermediary, and independently verifying whether a transaction was in fact confirmed.

Risks and limitations

Running a full node requires disk space, bandwidth, and maintenance, which leads many users to rely on nodes operated by third parties, reintroducing some trust. If a small number of operators concentrate most of the nodes, the network becomes more vulnerable. Initial synchronization of the entire history can also be time-consuming on large chains. Even so, it is by running your own node that you achieve the greatest degree of independence and privacy when querying the network.