An equity option allows investors to fix the price for a specific period of time at which an investor can purchase or sell 100 shares of an equity for a premium (price), which is only a percentage of what one would pay to own the equity outright. This allows option investors to leverage their investment power while increasing their potential reward from an equity’s price movements.

With straddles (long in this example), you as a trader are expecting the asset (like a stock) to be highly volatile, but don't know the direction in which it will go (up or down). When using a straddle strategy, you as the trader are buying a call and put option at the same strike price, underlying price and expiry date. This strategy is often used when a trader is expecting the stock of a particular company to plummet or skyrocket, usually following an event like an earnings report. For example, when a company like Apple  (AAPL) is getting ready to release their third quarter earnings on July 31st, an options trader could use a straddle strategy to buy a call option to expire on that date at the current Apple stock price, and also buy a put option to expire on the same day for the same price.

If there’s a company you’ve had your eye on and you believe the stock price is going to rise, a “call” option gives you the right to purchase shares at a specified price at a later date. If your prediction pans out you get to buy the stock for less than it’s selling for on the open market. If it doesn’t, your financial losses are limited to the price of the contract.
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.
For example: A trader in October 2016 agrees to deliver 10 tons of steel for INR 30,000 per ton in January 2017 which is currently trading at INR 29,000 per ton.  In this case, trade is assured because he got a buyer at an acceptable price and a buyer because knowing the cost of steel in advance reduces uncertainty in planning. In this case, if the actual price in January 2017 is INR 35,000 per ton, the buyer would be benefitted by INR 5,000 (INR 35000-INR 30,000). On the other hand, if the price of steel becomes INR 26,000 per ton then the trader would be benefitted by INR 4,000 (INR 30,000- INR 26000)
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).