Block top - The block quantity and length on the blockchain (in blocks) on generation of the present block Nonce - The transaction number for the from address (bear in mind this starts at 0 so a nonce of 100 would actually be the 101st transaction submitted by this account) https://active-bookmarks.com/story20567533/blockchain-explorer-fundamentals-explained-https-fletcher-odonnell-thoughtlanes-net-exploring-further-the-world-of-blockchain