Block top - The block selection and duration of the blockchain (in blocks) on creation of the current block Nonce - The transaction selection for your from address (bear in mind this begins at 0 so a nonce of 100 would in fact be the a hundred and first transaction https://friendlybookmark.com/story20581921/5-simple-statements-about-blockchain-explorer-solana-explained-https-peatix-com-user-27717689