Conversely, a put option is a contract that gives the investor the right to sell a certain amount of shares (again, typically 100 per contract) of a certain security or commodity at a specified price over a certain amount of time. Just like call options, a put option allows the trader the right (but not obligation) to sell a security by the contract's expiration date. 
In case of futures, a buyer of a contract is said to be “long position holder” and a seller is “Short position holder”. In the case of futures, to avoid the risk of defaulting contract involves both parties lodging a certain percentage margin of value of contract with a mutually trusted third party. Generally, in gold futures trading, margin varies between 2%-20% depending on the volatility of gold in spot market.
With respect to an option, this cost is known as the premium. It is the price of the option contract. In our home example, the deposit might be $20,000 that the buyer pays the developer. Let’s say two years have passed, and now the developments are built and zoning has been approved. The home buyer exercises the option and buys the home for $400,000 because that is the contract purchased.
To reiterate, buying options in times of low volatility could prove to be advantageous should the volatility increase sharply. On the other hand, a lack of deviation in the price of the underlying asset will produce lower market volatility and even cheaper option premiums. Once again, pricing is relative and dynamic; "cheap" doesn't mean that it can't get "cheaper".
For years, the preferred method of trading options was to use a live broker with a securities firm because you would receive all the research you would need to make a judgment. But with the advances made by online brokerage companies in being able to provide you with that information, more people are trading commodity options online than ever before and they are paying a fraction of the commissions they would otherwise pay to a live broker. Since you will have more trades than you would if you were simply buying stock, you will have more money in your account.

In terms of valuing option contracts, it is essentially all about determining the probabilities of future price events. The more likely something is to occur, the more expensive an option would be that profits from that event. For instance, a call value goes up as the stock (underlying) goes up. This is the key to understanding the relative value of options.
You also can limit your exposure to risk on stock positions you already have. Let’s say you own stock in a company but are worried about short-term volatility wiping out your investment gains. To hedge against losses, you can buy a “put” option that gives you the right to sell a particular number of shares at a predetermined price. If the share price does indeed tank, the option limits your losses, and the gains from selling help offset some of the financial hurt.
Options on futures began trading in 1983. Today, puts and calls on agricultural, metal, and financial (foreign currency, interest-rate and stock index) futures are traded by open outcry in designated pits. These options pits are usually located near those where the underlying futures trade. Many of the features that apply to stock options apply to futures options.
The Problem arises if one party fails to perform. The trader may fail to sell if the prices of steel goes very high like for example INR 40,000 in January 2017, in that case, he may not be able to sell at INR 31,000. On the other hand, if the buyer goes bankrupt or if the price of steel in January 2017 goes down to INR 20,000 there is an incentive to default. In other words, whichever way the price moves, both the buyer and seller have an incentive to default.
A commodity market is a market that trades in primary economic sector rather manufactured products.  Soft commodities are agriculture products such as Wheat, coffee, sugar and cocoa. Hard commodities are mined products such as gold and oil. Future contracts are the oldest way of investing in commodities. Futures are secured by physical assets. Commodity market can includes physical trading in derivatives using spot prices, forwards, futures and options on futures. Collectively all these are called Derivatives.
Just like many successful investors, options traders have a clear understanding of their financial goals and desired position in the market. The way you approach and think about money, in general, will have a direct impact on how you trade options. The best thing you can do before you fund your account and start trading is to clearly define your investing goals.

The potential home buyer would benefit from the option of buying or not. Imagine they can buy a call option from the developer to buy the home at say $400,000 at any point in the next three years. Well, they can—you know it as a non-refundable deposit. Naturally, the developer wouldn’t grant such an option for free. The potential home buyer needs to contribute a down-payment to lock in that right.

However, for put options (right to sell), the opposite is true - with strike prices below the current share price being considered "out of the money" and vice versa. And, what's more important - any "out of the money" options (whether call or put options) are worthless at expiration (so you really want to have an "in the money" option when trading on the stock market).