Quiz Entry - updated: 2026.07.30
In the "do you need a blockchain?" framework, what is a writer versus a reader?
A writer changes the stored state (in a blockchain, that's a consensus participant / validator); a reader only creates, reads, or audits transactions without extending the chain.
The methodology borrows plain database vocabulary and maps it onto blockchains:
| Role | Database sense | Blockchain sense |
|---|---|---|
| Writer | Any entity that writes state | A consensus participant that accumulates transactions into a block and appends it (a.k.a. a validator) |
| Reader | Any entity that reads | Anyone submitting/reading/auditing transactions but not extending the chain |
The whole decision procedure turns on the writers — how many there are, whether they're known, and whether they're trusted. Readers barely affect the choice; they only decide public vs private at the very end. (Regulators and the people who maintain the blockchain software are considered out of scope.)
Go deeper:
Consensus (computer science) (Wikipedia) — what a "writer"/validator actually does: agree on shared state despite faulty or hostile peers.