Blockchain transactions can now include metadata, providing additional information or context to users. On-chain metadata is stored directly on the blockchain, while off-chain metadata is referenced in the transaction but stored externally. Examples of metadata include timestamps, transaction details, smart contract data, digital signatures, gas fees, and nonfungible token metadata. Blockchain metadata has applications in supply chain management, digital identity, smart contracts, NFTs, and healthcare. However, challenges such as scalability, data security, and oracle reliability must be addressed for sustainable technology advancement and widespread adoption.