The griprail is attached to the guardrail. They are two separate things.

In the same way you have something smooth and continuous to hold onto inside your house, you need something on the outside stairs as well. It must be graspable and returned against the posts to avoid ensnaring purse straps and jacket pockets.

If you plan to build your own deck, be sure to get a copy of these strict code requirements from your building inspection department. This, and stairs in general, is the number one reason that decks done by homeowners fail inspection.