Where do you do business?
Sets your books currency, tax region, and default time zone. Everything is changeable later, and Corzova supports unlimited currencies as you grow.
A note on the three currencies in Corzova
Transaction currency is what your customer or vendor actually paid in. Functional currency (set above) is your books currency. Reporting currency is what consolidated reports roll up to (defaults to functional).
You don't need to think about this now — it just means Corzova handles foreign-currency invoices and FX revaluation natively. (Invariant #2.)