What is the point of suspense in a story?

Suspense adds tension to a story.  The two items come hand in hand.  Suspense can be scary, moody, exciting, etc., but in all cases it creates tension in the reader or the viewer.  Alongside tension is stress.  That is why a lot of people sometimes use "tense" and "stress" interchangeably.  "I'm super stressed this week."  "I'm so tense right now that I might vomit."  Suspense brings those emotions to the reader or the viewer, because usually the outcome of the suspenseful part is completely unknown.  Will the hero character live?  Will he die?  What will happen to the innocent civilians?  Where is that giant shark?  In all of those questions one thing is clear, the story teller has not given the viewer a clear indication of what will happen.  The fear of the unknown is suspenseful and creates stress and tension.