A Bitcoin node is a computer that participates in the Bitcoin network by validating transactions and blocks. Each node maintains a copy of the entire Bitcoin blockchain, which is the record of all transactions since Bitcoin’s inception.

There are different types of nodes. Full nodes verify every transaction and block against Bitcoin’s consensus rules, ensuring that all network participants follow the same protocol. They provide security and support to the network by rejecting invalid transactions and blocks. Lightweight nodes, or SPV nodes, take a different approach. They do not store the entire blockchain but instead rely on full nodes for information.

This makes them less resource-intensive but also means they have less security. Operating a Bitcoin node contributes to the decentralization and resilience of the network. Nodes can be run on personal computers, specialized hardware, or cloud services. By running a node, individuals help maintain the integrity and availability of the Bitcoin system. Anyone can set up a node, further promoting the principle of an open and accessible financial network.