# Design

The Currency Module introduces the following concepts:

## Currency

Each currency of interest is represented in Tryton by a currency record. These currencies are used together with a numeric value to represent an amount of money. Tryton can convert monetary amounts from one currency to another using the exchange Rate <model-currency.currency.rate> for a given date. This is important for multi-currency transactions, and if you want to manage money in a range of different currencies.

See also

Currencies can be found by opening the main menu item:

> Currency ‣ Currencies

## Rate

The exchange rates that are used when converting money between Currencies <model-currency.currency> are saved next to their associated currencies. As exchange rates vary over time they are stored along with the date from when they apply. All exchange rates are relative with respect to each other.

## Scheduled Rate Updates

The Exchange Rates <model-currency.rate> can be automatically updated using a Scheduled Task <trytond:model-ir.cron>. When the scheduled task is run it uses the external source to fill in the missing rates since the last update. The frequency determines which dates get rates.

See also

Scheduled Rate Updates can be found by opening the main menu item:

> Currency ‣ Scheduled Rate Updates