Linking blocks

As we know, blocks are linked in a blockchain using references, just like in a linked list, but here the blocks are linked by referencing the hash value (identifier) of the previous block. Each full node in a blockchain network will maintain a complete blockchain and append a new block whenever it has one to append. Due to the decentralized nature of the blockchain, each node will verify the block before linking it to the local blockchain record.

The computed hash value of each block is the combination of the hash of the previous block and its own block data. This results in a dependency between neighboring blocks and nearly unbreakable links:

Satoshi explained how the concept of timestamping should be used. All the items are hashed and the block is timestamped, meaning that the subsequent block will include this timestamp, creating an ordered chain of blocks.

Each node in the blockchain network follows a simple process for appending new blocks to its existing local blockchain. Whenever a node receives a block from the network, it checks for the previous block hash. If the hash value matches with the hash value of the last block on the node's local blockchain, then the node accepts this block and appends it to the current blockchain. As long as this is the longest known blockchain, the blocks would be considered valid by all the peers in the network in a PoW-based blockchain.