What is a Node?
A Bitcoin node is a computer running Bitcoin software that validates and relays transactions and blocks. Nodes are the backbone of the network—they enforce the rules that make Bitcoin work.
When you send bitcoin, your transaction propagates through thousands of nodes worldwide. Each one checks if it's valid before passing it along. If even one rule is broken, the transaction is rejected.
Types of Nodes
Full Node
- ✓ Stores entire blockchain (~600 GB)
- ✓ Validates all transactions & blocks
- ✓ Enforces all consensus rules
- ✓ Doesn't trust anyone else
- ✗ Doesn't mine blocks
Mining Node
- ✓ Everything a full node does
- ✓ Creates new blocks
- ✓ Competes for block rewards
- ✓ Selects which transactions to include
- ✗ Can't break consensus rules
Light Client (SPV)
- ✓ Stores only block headers (~60 MB)
- ✓ Verifies proof-of-work chain
- ✗ Can't validate all transactions
- ✗ Trusts full nodes for tx validity
- ✓ Good for mobile wallets
What Nodes Validate
Every full node independently checks every transaction and block against Bitcoin's consensus rules. Here's what a node verifies:
Validation Simulator
Watch a node validate an incoming transaction in real-time.
The Node Network
Nodes connect to each other in a peer-to-peer mesh network. There's no central server—each node is equal. When a new block is found, it propagates through the network in seconds.
Why Run a Node?
Running your own node means you don't have to trust anyone. Your node verifies everything independently.
| Benefit | Why It Matters |
|---|---|
| Privacy | Your transactions aren't broadcast through third parties |
| Security | You verify everything—can't be fooled by fake transactions |
| Sovereignty | You enforce the rules you agreed to—no one can change them on you |
| Network Health | More nodes = more resilient, more decentralized network |
Nodes vs Miners: The Key Difference
A common misconception: miners control Bitcoin. In reality, nodes control the rules, miners compete within those rules.
| Nodes | Miners | |
|---|---|---|
| Role | Validate & enforce rules | Create new blocks |
| Power | Can reject invalid blocks | Can choose tx inclusion |
| Income | None (volunteer) | Block rewards + fees |
| If they cheat | N/A—they just verify | Block rejected by nodes |
If miners tried to create coins out of thin air or spend someone else's bitcoin, every node would instantly reject that block. Miners can only win rewards by following the rules that nodes enforce.
Frequently Asked Questions
What's the difference between a node and a miner?
Miners create new blocks (they do the work). Nodes verify blocks (they check the work). You can run a node without mining, and miners can't cheat because nodes will reject invalid blocks.
How much does it cost to run a node?
A Raspberry Pi with external storage works. You'll need ~600GB for the full blockchain and bandwidth for syncing. Electricity cost is minimal—a few dollars per month.
Why should I run a node?
Privacy and sovereignty. When you use someone else's node, you trust them to tell you the truth. Your own node never lies to you—it's the ultimate self-custody tool.