A futures contract is simply a contract to buy or sell a financial instrument or other underlying asset at a predetermined price in the future. (links2exchange.net)
A put contract gives its owner the right to sell 100 shares of an underlying stock at a predetermined price (the strike) prior to the expiration date of the contract. (dividendempire.com)
These agreements aid forex dealers provide or to buy values at a predetermined price at a point of period in future. (cellphonesignal.com)