The use of options has increased dramatically over the years as a way to profit from or hedge against the volatile movements of stock prices. Not only can options be traded with stock as the underlying asset, they are also traded on foreign currency, interest rates and various indexes.

There are two kinds of stock options, American and European. American options can be exercised any time up to and including the expiration date of the option. However, European options can only be exercised on the date of expiration. Expiration dates follow three cycles: January, February and March. The January cycle is comprised of the first month of each quarter (January, April, July and October); the February cycle consists of the second month of each quarter (February, May, August and November); and the March cycle consists of the final month of each quarter (March, June, September and December).

Beyond the difference between American and European options, there are also more specific terms regarding expiration. Because expiration dates are usually identified just by a month, a specific date is identified within the expiration month that is used as an exact deadline. This deadline, for both types of options, is the third Friday of the expiration month. An investor normally has until 4:30pm Central time on the third Friday of the month to instruct their broker to exercise an option. 

To learn more about options, see the Options Basics Tutorial, The Four Advantages Of Options and Trading A Stock Versus Stock Options Parts I and Part II.