What is Bitcoin
Bitcoin is a network of computers that all keep an identical copy of the same ledger — who owns what. No bank, no company, no server in charge. Every participant checks the rules for themselves.
Miners propose. Nodes decide.
Miners spend electricity to bundle transactions into blocks and race to find a valid one first. That's their whole job: propose the next block.
But a miner's block only counts if it's valid. Every full node — anyone running the software, for free, on their own machine — independently checks that block against the rules: right format, no coins created from nothing, no rule-breaking. If a miner breaks a rule, every node on the network simply rejects the block. The miner wasted their electricity for nothing.
So who's actually in charge?
The nodes. Miners have brute force, but no authority — they can't make the network accept something nodes won't verify. Nodes have no hashpower, but total authority — they decide the rules, full stop.
This is the opposite of how most people assume power works. Size and spending usually win. In Bitcoin, the cheapest, most replaceable participant — a node, runnable on a Raspberry Pi — holds the actual veto. Miners can't outvote that. They can only follow it.
Why this matters
If there's only one piece of software everyone runs to be a node, that software's maintainer effectively writes the rules everyone else just rubber-stamps. Node diversity — multiple independent implementations, each separately checking the same rules — is what keeps that veto actually distributed, instead of resting on one person's judgment.
That's the whole point of this project.