What is the difference in how the exchange rate reflects the supply and demand for the currency between a flexible-exchange rate system and a fixed-rate exchange system?

Fixed Exhange-Rate System: currency system in which governments try to keep the values of their currencies constant against one another

Flexible Exchange- Rate System: allows the exchange rate to be determined by supply and demand. With a flexible exchange- rate system, exchange rates need not fall into any prespecified range.