You can lock in (what you believe to be) a reasonable price today and (if all goes well and momentum is in your favor) sell or buy back to make a profit later on. Of course, it can backfire if you’re wrong, making it a risky business.
One key difference is the fees structure. When you trade forex or CFDs, the commission involved is the spread between an asset’s sell and buy price. For futures, you’ll also pay a fixed commission per contract plus the exchange fees.