Chains
Up to this point, you learned that the assets that are transferred between entities are recorded in transactions and that transactions persist in append-only blocks. When a block is finalized, the block header that was created is added to the block that includes the nonce and the hash of the previous block, linking the two. The new block is identified with its own hash or blockId, and is used by the subsequent block, again linking the two.
Blockchain
The word blockchain, originally called block chain, is derived from the link between blocks. Because the hash of one block is based on the hash of the previous block, it is like a chain linking all the way back to the first, or genesis, block. This process confirms the integrity of the previous blocks in the chain. The following diagram shows how blocks are linked together using the previous block hash:
Every block is linked to its previous block through the block hash. The generated hash of a new block uses the hash of the previous block...
