On-chain data refers to information that is stored directly on a blockchain. This includes transaction records, contract details, and various other types of information that are permanently recorded and cannot be altered without consensus from the network.Each transaction adds a new block of data to the chain, which is then verified and accepted by participants in the network. On-chain data can provide transparency, traceability, and security, as everyone can access the same information and verify its accuracy.Examples of on-chain data include the number of tokens owned by a wallet, transaction histories, and smart contract code. This data is integral for many applications, such as decentralized finance (DeFi) platforms and non-fungible tokens (NFTs), as it underpins the functionality and trust in these systems. By storing information on the blockchain, users can interact with a decentralized ledger that promotes accountability and reduces the risk of tampering.