Call options have the following three Characteristics.

http://en.wikipedia.org/wiki/Call_option

All call options have the following three characteristics:

1 Strike price: this is the price at which you can buy the stock (if you have bought a call option) or the price at which you must sell your stock (if you have sold a call option).

2 Expiry date: this is the date on which the option expires, or becomes worthless, if the buyer doesn't exercise it.

3 Premium: this is the price you pay when you buy an option and the price you receive when you sell an option.

The initial transaction in this context (buying/selling a call option) is not the supplying of a physical or financial asset (the underlying instrument). Rather it is the granting of the right to buy the underlying asset, in exchange for a fee — the option price or premium.

Exact specifications may differ depending on option style. A European call option allows the holder to exercise the option (i.e., to buy) only on the option expiration date. An American call option allows exercise at any time during the life of the option.

Call options can be purchased on many financial instruments other than stock in a corporation. Options can be purchased on futures or interest rates, for example (see interest rate cap), and on commodities like gold or crude oil. A tradeable call option should not be confused with either Incentive stock options or with a warrant. An incentive stock option, the option to buy stock in a particular company, is a right granted by a corporation to a particular person (typically executives) to purchasetreasury stock. When an incentive stock option is exercised, new shares are issued. Incentive options are not traded on the open market. In contrast, when a call option is exercised, the underlying asset is transferred from one owner to another.