Nodes vs miners

Miners and nodes do two different jobs. Miners propose: they spend energy to order transactions into the next block. Nodes dispose: they check the block and decide whether to accept it.

A miner cannot change the rules alone

If a miner produces a block that breaks a rule, more coins than allowed or a spent output spent again, every node rejects it. The miner keeps the electricity bill and gets no reward. Their hashrate gives them a say on the order of valid transactions, not on what is valid.

• Miners decide which valid transactions go into the next block, and in what order.
• Nodes decide which blocks are valid, using rules they run themselves.
• Miners need the coins they earn to be accepted by the users and businesses running nodes.