Block top - The block selection and duration of the blockchain (in blocks) on creation of the current block Nonce - The transaction quantity for your from address (Keep in mind this begins at 0 so a nonce of 100 would actually be the 101st transaction submitted by this account) https://nimmansocial.com/story10499969/a-review-of-blockchain-explorer-xrp-https-squareblogs-net-heartgarlic3-delving-into-blockchain-explorers