There are different types of currency trading. You can do spot currency trading where you buy the currency at the current value of the purchase, and you can sell it the same way to, for the price at that particular point in time. You can also do futures trading where you can buy the option to buy and sell the currency at a certain, specified price. Lastly, the third kind is currency options trading. This is where you will be able to buy and sell the currencies only within a certain time period. if you are confused, I will hopefully be able to clear it up for you.
Essentially, you'll buy the option to buy and sell the various currencies against each other in a certain time frame. Sometimes that time frame is an hour, a day, a week, or even a month. You are basically hoping that the price will increase in the certain time window, so that you will be able to make a profit.
This can definitely be fun and exciting, but you need to do your due diligence. You can't just jump in and start trying to wing it hoping you can make some money. The currency markets fluctuate quite a lot, and so while you may get lucky once, luck has very little to do with currency options trading.
If you want an even more simplified version of options trading, then you can start to look at Binary Options. These types of options give you two choices and a time frame. The time frames vary and can be minutes to months. Essentially, you'll just have to figure out if the currency will increase in value or decrease in value in the certain time frame. It doesn't matter how much it fluctuates, as long as at the end of the time period, it is higher if you predicted higher or lower if you predicted that. You can earn anywhere from 60-75% on your investment for getting the binary options trades correct.