Options are powerful because they can enhance an individual’s portfolio. They do this through added income, protection, and even leverage. Depending on the situation, there is usually an option scenario appropriate for an investor’s goal. A popular example would be using options as an effective hedge against a declining stock market to limit downside losses. Options can also be used to generate recurring income. Additionally, they are often used for speculative purposes such as wagering on the direction of a stock.
Puts are more or less the mirror image of calls. The put buyer expects the price to go down. Therefore, he pays a premium in the hope that the futures price will drop. If it does, he has two choices: (1) He can close out his long put position at a profit since it will be more valuable; or (2) he can exercise and obtain a profitable short position in the futures contract since the strike price will be higher than the prevailing futures price.
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.