Block top - The block selection and duration of the blockchain (in blocks) on generation of the present block Nonce - The transaction number for your from address (bear in mind this begins at 0 so a nonce of 100 would really be the 101st transaction submitted by this account) https://keybookmarks.com/story20841612/blockchain-explorer-tron-secrets-https-rentry-co-4vomqtzo