Miners vs Nodes

Miners and nodes are often described interchangeably in casual Bitcoin discussion. They’re not the same thing. Understanding the difference clarifies something important about how power is distributed in Bitcoin.

Miners are the producers. They compete to find valid blocks, doing the proof of work that earns them the block reward. Mining requires significant specialised hardware and electricity. Most mining is now done by large industrial operations. The top ten mining pools control a substantial portion of global hash rate.

This concentration sounds concerning until you understand nodes.

Nodes are the validators. They receive every block miners produce and check it against Bitcoin’s rules. A node doesn’t need specialised hardware — a modest computer and an internet connection is sufficient. Tens of thousands of nodes run worldwide, operated by individuals, businesses, exchanges, and enthusiasts.

Here’s the key: miners cannot change the rules. Only the node network can effectively change the rules — because nodes decide what they’ll accept. A miner who produced a block violating Bitcoin’s supply cap would have that block rejected by every honest node. The miner would have wasted the energy. The fraudulent coins would never be recognised.

In 2017, a group of large mining companies and exchanges tried to change Bitcoin’s rules to allow larger blocks. They had significant hash rate. They had industry backing. They announced a fork that would have changed Bitcoin fundamentally.

The node network didn’t adopt it. Users ran nodes enforcing the original rules. The proposed change failed. The miners backed down.

Miners produce Bitcoin’s history. Nodes decide what history is valid. Both matter. Neither is in charge alone.

Tomorrow: the mempool — the waiting room for Bitcoin transactions.

— The Daily Bit