These are the base formats, some of which are common to almost all electronic document management systems.
Numbers with a fixed format relating to money, such as €10.00
Floating point number
Numbers with a decimal part, such as 45.18492.
Numbers without a decimal part, such as 357.
This is the most generic type available, it can fit any text.
When you are not sure, you should always use the most generic type possible String, and then try a different type if the result does not match your expectations.
A monetary amount, relative to the taxable amount, drawn from several available.
An amount of money, relative to the amount of the fees, drawn from several available.