Why do multiple countries share "Dollar" as the same currency name?

submitted by Shadow79 to asklemmy 12 points | 4 comments There are about 30 countries that share the same currency name “Dollar” (USA, Canada, Australia, New Zealand, Brunei, Singapore, Barbados, Fiji, Cayman Islands & etc.). but they are not related to each other besides their name, since they have different values from one another, even though they share the same currency symbol: only thing that distinguishes them apart is the country prefix tied to $ (like US$, AU$, NZ$, C$, CI$, FJ$, SG$, Bds$, JA$, B$, etc.).