Block height - The block quantity and size on the blockchain (in blocks) on development of the present block Nonce - The transaction selection for the 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://listfav.com/story21989189/detailed-notes-on-blockchain-explorer-unconfirmed-transaction-https-www-instapaper-com-p-16864836