My understanding of a block in blockchain is that it is a data structure that contains information like Block Size, Block Header, Transaction Counter and then Transactions. Deeper in the Block Header we have information like Previous Block Hash, Merkle Root, Timestamp, Difficulty Target and Nonce.
Recently, I appeared for an interview and my above explanation of what actually makes a block in blockchain was not very much accepted by the interviewer and he quoted that my response was not up to the mark.
Though my question is not related to coding per se, I wish to clear my concepts here. Will appreciate if someone can guide me here as to what could have been the best technical answer in my case. Will appreciate a pointer to an article or any other document which explains these underlying concepts in details.