- Onchain: The execution of the STF of a blockchain, done by the Validator set, which leads to the State of the blockchain being updated. All of this work happens within the Consensus Algorithm’s umbrella and is guaranteed to be Trustless and secure. Example:
- Validators producing a new block
- Offchain: Any other work that is done outside of the above. Examples:
- Blockchain validators might run auxiliary services on their Blockchain Node that act as oracles
- Blockchain nodes might establish connections to other entities to help them with finding the optimal block to produce, as done in Proposer-Builder Separation (PBS).
- Every time you read any data from the blockchain, it does not involve a Transaction, and it does no involve any onchain work, as reading data does not require the execution of the STF.