Each block of blockchain includes a block header, transactions, transaction counter and blocksize.
A block header is like the metadata at the top of a block of transactions. It is used to identify a particular block on an entire blockchain and is hashed repeatedly to create a proof of work for mining rewards. It includes everything else apart from transactions: The hash of the last block header, Timestamp, Nonce and Difficulty.
Transactions record information about the sender, receiver, transaction amount and sender’s digital signature, which is the main content in each block.
Transactions counter refers to the number of transactions in each block.
Blocksize represents the size of the data in each block. Currently, the maximum block size is 1MB. It is possible that the block size limit will increase in the future.