• Call Options – Give the buyer the right, but not the obligation, to buy the underlying at the stated strike price within a specific period of time. Conversely, the seller of a call option is obligated to deliver a long position in the underlying futures contract from the strike price should the buyer opt to exercise the option. Essentially, this means that the seller would be forced to take a short position in the market upon expiration.
A longer expiration is also useful because the option can retain time value, even if the stock trades below the strike price. An option’s time value decays as expiration approaches, and options buyers don’t want to watch their purchased options decline in value, potentially expiring worthless if the stock finishes below the strike price. If a trade has gone against them, they can usually still sell any time value remaining on the option — and this is more likely if the option contract is longer.
Call writers and put writers (sellers), however, are obligated to buy or sell if the option expires in-the-money (more on that below). This means that a seller may be required to make good on a promise to buy or sell. It also implies that option sellers have exposure to more, and in some cases, unlimited, risks. This means writers can lose much more than the price of the options premium.

For example: A steel manufacturer importing coal from Australia currently and in order to reduce the volatility of changes in prices he always hedges the coal purchases on a 3 monthly forward contract where he agrees with the seller on day one of financial quarter to supply coal at defined price irrespective of price movements during quarter. So in this case, the contract is forward/future and buyer has an intention to buy the goods and no intention of making profit from price changes.

Similarly, if you believe the company’s share price is going to dip to $80, you’d buy a put option (giving you the right to sell shares) with a strike price above $80 (ideally a strike price no lower than $80 plus the cost of the option, so that the option remains profitable at $80). If the stock drops below the strike price, your option is in the money.

Decide whether you think a commodity will sell for more or for less at some designated time in the future, then buy either a “put” or a “call” option. For example, you think that corn will cost more three months from now than it does now, so you will buy a “call” option on 100 bushels of corn which, in effect, locks in the cost of that commodity. Before the option expires, hopefully the price will go up, so your option will be worth more. Conversely, you will buy a “put” option if you think the price of the commodity will be less than it is today.

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).