As the futures graph indicates clearly, the downside risk of buying a future is large if you take a wrong position. A major advantage of an option is to keep the profit potential while limiting your downside risk.
A call option is a right to buy a financial asset at a price fixed today (the exercise price or strike) with delivery at a future date.
A put option is a right to sell a bond at a price fixed today with delivery in the future.
The difference between an option and a financial future stands in one word. The option is a right, while the future is an agreement. As the holder of an option may or may not exercise his right, an option will only be exercised if it brings a gain to the holder of this option.