The rights to buy a specified currency at a designated price within a specific period of time.
The price at which the owner is allowed to buy that currency is known as the exercise price or strike price.
No obligation to exercise
Call options are desirable when one wishes to lock in a maximum price to be paid for a currency in the future.
If spot rate of the currency rises above the strike price, owners of call options can “exercise” their options by purchasing the currency at strike price, which will be cheaper than the prevailing spot rate.