Doubts on virtuemart database's fields

[Alesorta]

Hi,

I'm working on virtuemart - ADempiere ERP integration, but I have some question regarding fields of  virtuemart's database.

I have exported the table with CSVimproved and I can't understand the function of some fields.

-What is the virtuemart customer number? and virtuemart custom id?

-Assuming that fields "country_x_code" and "state_x_code" are for americans (am I correct if I say, for example, country=USA state=Ohio?) how can I change the "state" voice. In fact I'm in Italy and we have contry and regions, non states.