1 Bronze coin: lowest amount of money and used as the daily currency of commoners.
1 Silver coin: A good currency usually used by nobles and their children.
1 Gold coin: A high currency used by the head of noble families.
1 Red coin: A higher grade currency used by a king.
1000 bronze coin = 1 silver coin
1000 silver = 1 gold coin
1000 gold = 1 red coin