The blockchain is the large ledger of the Bitcoin network, and each block is equivalent to a page in the ledger. So what information is recorded in the "ledger"? At present, each block of Bitcoin mainly records data such as block header, transaction details, transaction counter and block size.
"Block header" contains all information except transaction information, mainly including the hash value of the previous block header: it is used to ensure that blocks are connected in sequence;
"Transaction Details" details the sender of each transaction, The digital signature of the recipient, the amount and the sender is the main content in each block.
The "transaction counter" represents the number of transactions contained in each block.
"Block size" indicates the size of the data of each block. Currently, each block is limited to less than 1MB, and it does not rule out the possibility of expansion in the future.
"Timestamp" records the generation time of the block;
The "nonce" is the answer of the arithmetic question that the miners of the whole network PK together;
"Difficulty Target" The difficulty factor of the arithmetic question is scored.