Answer:
-The amount of one currency that can be traded for a unit of another currency is the exchange rate.
-Many exchange rates float, or constantly change.
-It is best to travel abroad when the exchange rate gets you more units of a foreign currency.
Step-by-step explanation:
The exchange rate is how much your currency is worth by comparison to a different currency. Those values are affected by local and international markets, government, and other things, so it's cheaper for you to travel when you can buy other currency when the value of that coin is lower. This makes you able to spend more there for much less money.