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. 

Spreads use two or more options positions of the same class. They combine having a market opinion (speculation) with limiting losses (hedging). Spreads often limit potential upside as well. Yet these strategies can still be desirable since they usually cost less when compared to a single options leg. Vertical spreads involve selling one option to buy another. Generally, the second option is the same type and same expiration, but a different strike.
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".
As an example, let's say an initial margin amount of $3,700 allows an investor to enter into a futures contract for 1,000 barrels of oil valued at $45,000—with oil priced at $45 per barrel. If the price of oil is trading at $60 at the contract's expiry, the investor has a $15 gain or a $15,000 profit. The trades would settle through the investor's brokerage account crediting the net difference of the two contracts. Most futures contracts will be cash settled, but some contracts will settle with the delivery of the underlying asset to a centralized processing warehouse.

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.
With this strategy, the trader's risk can either be conservative or risky depending on their preference (which is a definite plus). For iron condors, the position of the trade is non-directional, which means the asset (like a stock) can either go up or down - so, there is profit potential for a fairly wide range. To use this kind of strategy, sell a put and buy another put at a lower strike price (essentially, a put spread), and combine it by buying a call and selling a call at a higher strike price (a call spread). These calls and puts are short.  
The price at which you agree to buy the underlying security via the option is called the "strike price," and the fee you pay for buying that option contract is called the "premium." When determining the strike price, you are betting that the asset (typically a stock) will go up or down in price. The price you are paying for that bet is the premium, which is a percentage of the value of that asset.