Currency data type details

This is more of an informational question regarding the Currency. In all the examples I’ve seen in the ERPNext doctypes, the Options is set to either Company:company:default_currency or currency. Where is this being grabbed from / what is the format? I’m assuming they are grabbing from the field names, but I’m not sure about the formatting.

I’m not sure I understand how the Currency data type works. How do I convert between currencies using these data types? What differentiates them between floats or any other data types.

If there is any documentation on this, please just point me in the right direction. I can’t seem to find it.

if its currency, its the fieldname, if Company:company:default_currency, the its

reference_doctyep:fieldname:fieldname_in_reference_doctype. For this the doctype must be loaded already in the client (Company is loaded via boot)

Can you give an example of what you are trying to achieve?