We can first draw an example of a blockchain:
Then the first block is the first block generated in the system called the genesis block.
The last block is the most recent block
Each block contains a hash pointer to the previous block, so each block has a small H(); the last block has a H() (hash value) stored in the system
So what are the benefits of this data structure?
Everyone needs to know that when we get the hash, we combine the contents of the entire block of the previous block to get the hash, so that we can realize the tamper-evident log
So the blockchain affects the whole body: if you change any previous block, all subsequent blocks will be changed accordingly.
Therefore, the blockchain only needs to save the last hash value to detect whether any part of the block has been changed.
For ordinary chains, changing one element has no effect on other elements in the linked list