Contract Months (Time): All options have an expiration date; they only are valid for a particular time. Options are wasting assets; they do not last forever. For example, a December corn call expires in late November. As assets with a limited time horizon, attention must be accorded to option positions. The longer the duration of an option, the more expensive it will be. The term portion of an option's premium is its time value.
The market value of that home may have doubled to $800,000. But because the down payment locked in a pre-determined price, the buyer pays $400,000. Now, in an alternate scenario, say the zoning approval doesn’t come through until year four. This is one year past the expiration of this option. Now the home buyer must pay the market price because the contract has expired. In either case, the developer keeps the original $20,000 collected.
Sometimes corporations enter the forex market in order to hedge their profits. A US company with extensive operations in Mexico, for example, may enter into a futures contracts on US dollars. So, when it comes time to bring those Mexican profits home, the profits earned in pesos will not be subject to unexpected currency fluctuations. The futures contract is a way of securing an exchange rate and eliminating the risk that peso will lose value versus the dollar, making those profits worth less in dollars.
The fee you are paying to buy the call option is called the premium (it's essentially the cost of buying the contract which will allow you to eventually buy the stock or security). In this sense, the premium of the call option is sort of like a down-payment like you would place on a house or car. When purchasing a call option, you agree with the seller on a strike price and are given the option to buy the security at a predetermined price (which doesn't change until the contract expires).