Block top - The block selection and duration of the blockchain (in blocks) on creation of the current block Nonce - The transaction variety for your from address (bear in mind this starts at 0 so a nonce of 100 would really be the 101st transaction submitted by this account) https://bookmarkalexa.com/story5839527/detailed-notes-on-blockchain-explorer-unconfirmed-transaction-https-www-webwiki-ch-cryptoexplorerhub-com