A contract is the mechanism through which an investor will access the futures market. A contract is the instrument that is either bought or sold on a futures exchange.
A contract gives the trader the exposure to the underlying market he or she wishes to participate in. Future contracts on an exchange are standardised. Contracts are identical and thereby interchangeable with one another.
The minimum size a trader can participate in is one contract. Contracts may represent different underlying assets. The details of each standardised contract are published by the exchange. Contracts may be on indices, individual equities, commodities, currencies, interest rates and agricultural commodities.