Long put options are options that are purchased. They give the purchaser the right but not the obligation to sell shares of an underlying security at the strike price until the expiration date....

If the price of the underlying security is greater than or equal to the strike price of the option, then the option expires and is not automatically exercised. The option likely expires worthless.

If the price of the underlying security is less than the strike price of the option, then the option will be exercised. The option purchaser will be able to sell shares of the underlying (generally 100 shares) at the strike price.