# On-chain

> Recorded on the blockchain itself — permanent, public, verifiable by anyone — as opposed to off-chain data in someone's database.

The distinction decides what a claim is worth: 'we sent you the tokens' is a statement; a transaction id is proof anyone can verify on an explorer. On-chain data has the chain's properties — immutable, timestamped, expensive per byte — which is why large payloads live off-chain with only their hash anchored on it.

For business use the honest split matters: the proof, the ownership record and the settlement belong on-chain; the image, the document and the personal data do not. Putting customer data on an immutable public ledger is a GDPR answer nobody wants to give.

## Related terms

- https://dfieldsolutions.com/en/glossary/smart-contract.md
- https://dfieldsolutions.com/en/glossary/solana.md
- https://dfieldsolutions.com/en/glossary/merkle-proof.md

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Source: https://dfieldsolutions.com/en/glossary/on-chain
DField Solutions — Dunakeszi, Hungary — dezso@dfieldsolutions.com
Booking: see https://dfieldsolutions.com/en/contact