Blockchain is a distributed ledger technology that secures data transactions and verifies them by multiple parties. It is decentralized, transparent, secure and auditable. The blockchain structure is a complex stack of multiple layers, each with its distinct role and function . At the base of this structure of blockchain is the data layer, where the actual blocks reside, containing transactional information securely linked using cryptographic hashes . Each block includes the cryptographic hash of the prior block in the blockchain, linking the two . This creates a chain of blocks, hence the name blockchain. The header of a block contains the previous block hash, current block hash, nonce, Merkle root, and other details . The Merkle root is a type of data structure frame of different blocks of data. A Merkle Tree stores all the transactions in a block by producing a digital fingerprint of the entire transaction. It allows the users to verify whether a transaction can be included in a block or not . The timestamp is a string of characters that uniquely identifies the document or event and indicates when it was created . The nonce is a central part of the proof of work in the block. It is compared to the live target if it is smaller or equal to the current target. People who mine, test, and eliminate many Nonce per second until they find that Valuable Nonce is valid . The block header is hashed periodically by miners by changing the nonce value as part of normal mining activity . Three sets of block metadata are contained in the block header: Previous Block Address/ Hash, Timestamp, and Nonce .
The blockchain structure is designed to be decentralized, meaning that there is no central authority that controls the blockchain. Instead, the blockchain is maintained by a network of nodes that work together to validate transactions and add new blocks to the chain . The consensus algorithms in blockchain are used to maintain data stability in a decentralized network . Transactions can be validated quickly and invalid transactions would not be admitted by persons or miners who mining the crypto. It is not possible to delete or roll back transactions once they are included in the blockchain network. Invalid transactions do not carry forward further .
The blockchain structure has several key characteristics. Decentralization is one of the most important characteristics of blockchain architecture. In centralized transaction systems, each transaction needs to be validated in the central trusted agency (e.g., the central bank), naturally resulting in cost and the performance jam at the central servers. In contrast to the centralized mode, a third party is not needed in the blockchain . Blockchain security methods include the use of public-key cryptography . Open blockchains are more transparent than traditional ownership records, which are often kept private. Blockchain technology allows for a complete history of all transactions to be stored on a single ledger, which can be accessed by anyone with an internet connection .
In conclusion, blockchain structure is a complex stack of multiple layers, each with its distinct role and function. It is designed to be decentralized, transparent, secure and auditable. The blockchain structure has several key characteristics such as decentralization, transparency, and security. It is a distributed ledger technology that secures data transactions and verifies them by multiple parties. The blockchain structure is maintained by a network of nodes that work together to validate transactions and add new blocks to the chain. Transactions can be validated quickly and invalid transactions would not be admitted by persons or miners who mining the crypto. It is not possible to delete or roll back transactions once they are included in the blockchain network. Invalid transactions do not carry forward further.
: [GeeksforGeeks](https://www.geeksforgeeks.org/blockchain-structure/)
: [Komodo