Full Node

A full node is a computer program that connects to a blockchain network, downloads blockchain data, and independently checks that transactions and blocks follow the network’s rules. Unlike a lightweight wallet, which often asks other servers for information, a full node can verify things for itself, such as whether coins were already spent, whether a block is valid, and whether consensus rules are being followed. Full nodes may store the entire transaction history, or use pruning to keep only the data needed for validation while discarding older raw data.

Full nodes matter because they help keep a blockchain decentralized and trustworthy. They relay valid transactions and blocks to other peers, reject invalid ones, and let users confirm their own balances without trusting an exchange, wallet provider, or block explorer. For example, using a Bitcoin full node with your wallet is like checking a receipt against the store’s official accounting rules yourself, rather than asking someone else whether the payment happened. Miners and validators often use full nodes, but running one does not necessarily mean you create new blocks or earn rewards.