A computer running blockchain software that maintains a copy of the ledger and helps validate transactions.
A node is any computer running a blockchain's software that maintains a copy of the ledger and participates in the network. Nodes are the backbone of decentralization — the more independent nodes running, the more resilient and censorship-resistant the network becomes. Different types of nodes serve different functions: full nodes store the entire blockchain history and validate every transaction independently; light nodes store only block headers for quick verification; archive nodes store all historical states for data queries; and validator nodes (in PoS) or mining nodes (in PoW) actively produce blocks. Running a full node allows anyone to independently verify the blockchain without trusting any third party. Bitcoin has ~15,000 full nodes, Ethereum has ~6,000 consensus nodes plus ~5,000 execution clients. Node requirements vary dramatically — Bitcoin nodes can run on a Raspberry Pi, while some chains require powerful servers.
A node is a computer running blockchain software that maintains a copy of the ledger, validates transactions, and propagates data to other nodes in the network. Nodes are the fundamental infrastructure of decentralization — the more independent nodes, the harder it is for any single entity to manipulate the network. Full nodes download and verify every transaction since the blockchain's genesis, independently validating the entire history without trusting anyone else. Light nodes store only block headers and verify transactions using cryptographic proofs, requiring less storage but providing weaker verification guarantees. Validator nodes in PoS networks also participate in block production and consensus. The ability for anyone to run a node is central to the decentralization thesis: Ethereum has ~8,000+ full nodes worldwide, Bitcoin has ~15,000+, while chains with higher hardware requirements may have fewer hundred. Lower node counts increase centralization risk.
Anyone can run a Bitcoin full node on a $50 Raspberry Pi with a 1TB drive — independently verifying every transaction since 2009 without trusting Coinbase, Binance, or any other intermediary.
Yes — Bitcoin and Ethereum nodes can run on a standard computer with ~1TB SSD storage and 8GB+ RAM. Dedicated hardware like Raspberry Pi with SSD is popular for always-on nodes. Running a node gives you maximum privacy (no reliance on third-party data) and contributes to network decentralization. Some chains (Solana) have higher hardware requirements.