Numismatics - Notaphily
Numismatics is the study or collection of currency, including coins, tokens, paper money, medals and related objects.
Specialists, known as numismatists, are often characterized as students or collectors of coins, but the discipline also includes the broader study of money and other means of payment used to resolve debts and exchange goods.
Notaphily is the study and collection of paper currency, and banknotes. A notaphilist is a collector of banknotes or paper money, particularly as a hobby.