Identifying and authenticating coins and paper money can be very challenging; not only are there numerous variations on all the world’s currencies, but the field is also a popular target for counterfeiters. Whenever feasible, seek out expert hobbyists, collectors, and professionals amongst your friends and family members or in your local community to help you with identification and authentication of these items. The value of a piece of currency is ultimately determined by demand, availability, condition, and grading.