In the context of blockchain technology, data blocks refer to individual units of data that are bundled together and added to the blockchain. Each block typically contains a set of transactions, as well as a header that includes metadata such as a timestamp, a unique identifier (hash), and a reference to the previous block in the chain. Once a block is added to the chain, it becomes a permanent part of the ledger and cannot be altered or deleted without consensus from the network. By organizing data into blocks and chaining them together, the blockchain ensures a secure and tamper-proof record of all transactions on the network.