Bitcoin
A ledger for money
- Moves a native asset (BTC) between addresses.
- Keeps a public list of who can spend what.
- Stays honest with proof of work — energy as the cost of cheating.
- Scripts exist, but the machine is built to be money first.
Bitcoin vs Ethereum
Same honesty model. Different machine.
Bitcoin is a shared ledger for money. Ethereum is a shared ledger that also runs programs. Neither is a company. Neither is a bank.
Ethereum
A ledger that runs programs
- Moves ETH — and also hosts contracts that hold their own ledgers.
- Same public-list idea: keys, signatures, append-only history.
- Stays honest with proof of stake — collateral as the cost of cheating.
- Tokens, NFTs, and apps are programs on that machine, not extra blockchains you have to understand first.
If you already have the Bitcoin picture, Ethereum is that picture plus a vending machine bolted to the sidewalk. The rest of the primer is how the machine actually works.