Back to: Blockchain Basics
A node is a computer running the blockchain’s software and holding (some of) its history. Thousands of independent nodes, run by different people in different places, *are* the network — there is no central server room to find.
The species of nodes
– Full nodes verify everything: every transaction, every block, from genesis. The backbone of trustlessness. – Miners/validators also propose blocks (and earn rewards) on top of verifying. – Light clients check only proofs (Merkle branches) — enough for phones and browsers without downloading terabytes. – Archive nodes keep every historical state, serving explorers and analysts.
Why node distribution is the decentralization question
Count means little; *independence* means everything. Ten thousand nodes on three cloud providers in two countries can be switched off by two companies and one government request. Geography, ownership, hosting, and client diversity are the real metrics — exactly what W3D’s infrastructure pillar scores.
Can you run one?
On many chains, yes, on a laptop (Bitcoin, Ethereum light/full) — syncing takes time and disk, but no permission. On heavy chains (Solana-class), requirements price out hobbyists, which is itself a decentralization datum. Running a node is the most direct way to stop trusting and start verifying.
Every node is a vote that the rules are the rules. The more independent
> voters, the harder the election is to steal.
Next lesson: consensus without bosses.