So, the value of an IBM stock option, for example, will be largely based on IBM's current stock price. For now, let's stick with stocks. A stock option is the right to either buy or sell 100 shares of a stock at a predetermined price within a specific parameter of time in the future. You don't own the stock itself, but the right to buy or sell the stock. Buying a put would allow you to sell 100 shares of IBM at a predetermined price on or before that date.
Every option has an expiration date.
While you could conceivably hold a stock forever, options have a limited life span, usually just a couple of months. After that, it would cease trading altogether. Buying options isn't free. You pay a price called a premium, which is determined by several variables, all of which have to do with the likelihood that the option will be worth something by the time it expires. The first variable is the price of the underlying stock.