"On-chain" refers to data or transactions that are recorded directly on a blockchain, which is a decentralized digital ledger. This means that every transaction is verified and stored in a way that is transparent and immutable, making it difficult to alter or delete. Examples of on-chain activities include cryptocurrency transactions, smart contracts, and token transfers. In contrast to "off-chain" activities, which occur outside the blockchain and may require additional trust or intermediaries, on-chain processes rely solely on the blockchain's inherent security and consensus mechanisms. This ensures that all participants can independently verify the information without needing to trust a central authority, enhancing the overall integrity of the system.