A Parisian option which gives the holder the right to exercise during the whole life span of the option, including its maturity date. More precisely, the right to exercise is bound only by the barrier condition (knock in/ knock out feature), and that is in contrast with a European-style option whose exercise is subject to two conditions.

For example, if the option is of the type that activates beyond the barrier, the option holder cannot do or decide anything before the option is activated. Once the option is activated, then the option doesn’t have a barrier anymore, and is just a plain vanilla American option.