Calls and Puts
The buyer of an equity CALL option has purchased the right to buy shares of the underlying stock at the stated exercise price. For a call holder, it is only worth considering exercising the option if the current price of the underlying share is greater than the exercise price.
The buyer of an equity PUT option has purchased the right to sell the number of shares of the underlying stock at the stated exercise price. For a put holder, it is only worth considering exercising the option if the current price of the underlying share is less than the exercise price.