There are firstly simple collectors, who solely derive pleasure from collecting coins. However, there are also coin dealers, or professional numismatists, who authenticate or
grade coins for commercial purposes. The buying and selling of coin collections by numismatists who are professional dealers advances the study of money, and expert numismatists are consulted by historians, museum curators, and archaeologists. See, for example, the
International Association of Professional Numismatists (IAPN) and the
British Numismatic Trade Association (BNTA). There are also scholar numismatists or numismatic researchers working in public collections, universities or as independent scholars acquiring knowledge about monetary devices, their systems, their economy and their historical context. Coins are especially relevant as a source in the pre-modern period, with the likenesses of many ancient and medieval monarchs being known to us only through their depictions on coins. Examples of these different kinds of numismatist include
Walter Breen, a noted numismatist who was not an avid collector, and King
Farouk I of Egypt, an avid collector who had very little interest in numismatics.
Harry Bass by comparison was a noted collector who was also a numismatist. == Training and recognition ==