KoinlyticsA blockchain node is a computer that runs the protocol software and holds some subset of the chain's history. There are three main types.
Full node
- Runs full validation: verifies every block and transaction independently.
- Holds current state and recent history (typically last 128 blocks or 32 GB rolling for Ethereum with pruning).
- Required to participate in staking (Ethereum) or mining (Bitcoin).
- Hardware: 16 GB RAM, 2 TB SSD, decent CPU.
Archive node
- Full node + every historical state ever.
- Ethereum archive: 15 TB+.
- Required for querying historical state (block explorers, analytics).
Light node
- Downloads only block headers.
- Trusts full nodes to give correct state.
- Runs on a phone or laptop with minimal storage.
- Used by mobile wallets (Trust, some MetaMask configurations).
Why run your own
- No trust in third-party RPCs. Infura, Alchemy, and QuickNode see every request you make. Your own node = your own privacy.
- Censorship resistance. If the RPC is down or blocked (as happened during Tornado sanctions), you have direct chain access.
- Custom logic. Run subscribers, indexers, MEV detection, or research queries.
Cost / setup
A geth + Prysm setup on a NUC-class machine runs about $1,000 total hardware + electricity ~$15/month. Bitcoin full node: same or less. Setup time: 24-48 hours for initial sync.
What you get
Verification without trust. Every transaction you make can be broadcast through your own node, immune to third-party censorship or key logging.