The advantage is simple: It keeps the money flowing around the world.
A more complex answer would involve the exchange of goods and services, comparative value and advantage and some other rules...
Having a low exchange rate basically means that you can buy less foreign currency units with a single domestic currency unit. Thus your exports will become cheaper to foreigners since they can buy...
•The merchant business in which the contract with the customer to buy or sell foreign currency is agreed to and executed on the same day is known as ready transaction.•Thus in practice, the terms...