Your company's base currency (used for accounting), additional accepted currencies (for multi-currency invoicing), and FX rate sources.
Settings → Currency.
The currency your books are in. Set once at company creation; changing later requires care (existing transactions stay in their original currency).
Optional second currency for reports (e.g. base TZS, reporting USD). The system converts at the FX rate of each transaction's date.
Which currencies you accept on invoices + POS. Pick from the dropdown. Each accepted currency uses your configured FX source.
Automatic (daily refresh from a market data feed) or Manual (you key in rates daily). Most SMEs use Automatic.