Collecting banknotes

Banknotes collecting also known as notaphily. What are collectible banknotes and how valuable are they? A banknote is used for business negotiations as a promissory note issued by the bank and which the bearer can later on encash. Bank notes, as money, have evolved through time. Before, banknotes were originally an I.O.U. or a promise to repay a lender in gold, silver, or other bullion.