A node is a computer that connects to a blockchain network, maintains a copy of the ledger, and participates in validating and relaying transactions. Nodes are the backbone of any decentralized network.
Types of Nodes
Full Node: Stores the entire blockchain history and independently validates all transactions and blocks against the consensus rules. Provides the highest level of security and decentralization.
Light Node: Stores only block headers and relies on full nodes for transaction verification. Uses less storage and bandwidth.
Archive Node: Stores all historical states of the blockchain, not just the current state. Used by block explorers and analytics platforms.
Validator Node: A full node that also participates in block production (in PoS networks) by staking tokens.
Why Nodes Matter
The more nodes a network has, the more decentralized and censorship-resistant it becomes. Anyone can run a node — Bitcoin has over 15,000 reachable nodes, and Ethereum has thousands of validators. Running a node means you don't have to trust anyone else's copy of the ledger.