Dukatia deals with money and money without a currency just doesn't make sense. Per default there are two currencies: Euros and Us Dollars. An admin can edit or add more currencies. This would obviously be helpful if you live in a country that doesn't use either of those two currencies.
You could also add your favorite crypto currency.
Currencies are made up of a name and symbol. There is also the minor_in_major. This just describes the relationship between the minor and major part of a currency. For exmaple with Euros you have 100 Cents in every Euro, so the minor_in_major is 100. This is true for most currencies, but not all!
Using a minor_in_major that has a value other than 100 can lead to some weirdness in filtering tables!