Futures are contracts which entitles you to buy or sell the underlying (shares, commodities, currency etc) on a future date(Expiry Date) at a price agreed upon today. The price agreed upon will be based on the current Spot market. Your profit will be the difference between agreed price and the actual price on expiry date. An option is also a similar contract but the only difference is; in Option the buyer have right to either execute or not execute the contract while in futures execution is compulsory.