What is On-chain?
A transaction recorded in a Bitcoin block, as opposed to one settled off-chain in a channel or inside a custodian's ledger.
On-chain settlement is final, public and costs block space. Off-chain settlement is cheap and fast but carries a different trust or liveness assumption depending on the mechanism.
The distinction matters for data as well as payments: on-chain metrics see only on-chain activity, which is a shrinking share of total economic use.
Related terms
Lightning Network
A network of payment channels built on Bitcoin that settles small payments off-chain, using the base layer…
Comment ça marcheTransaction
A signed instruction consuming one or more UTXOs and creating new ones. Once confirmed it cannot be reversed.
On-chain dataAdresses actives
The count of unique addresses appearing in transactions over a period, usually one day.
This definition is part of the Bitcoin Logical glossary. For the fuller explanation, start with Apprendre, or see the live numbers on Le Signal Bitcoin.