Block structure refers to the way data is organized within a block on a blockchain. Each block contains a set of transactions that have been validated and grouped together. Typically, a block includes a header and a body.

The header contains metadata, such as the block’s unique identifier (hash), the hash of the previous block, a timestamp, and a nonce used for mining. This information is crucial for maintaining the integrity and security of the chain.

The body of the block contains the list of transactions. Each transaction includes details like the sender, receiver, amount, and a cryptographic signature. This structure ensures that all transactions are transparent and can be verified by anyone who has access to the blockchain.

The organization of data in blocks and their connections form a chain, which is central to how blockchain technology maintains a secure and tamper-resistant ledger. This structure is what enables features like traceability and immutability, making it a foundational aspect of blockchain systems.