Suspense is the apprehension of what is going to happen. In films, suspense can foreshadow future events, create drama, build tension and it can also leave unanswered questions which will lead the audience to be desperate to know what is going to happen. The 'bomb effect' (Alfred Hitchcock) can create suspense because the audience know more than the characters on screen. Suspense is created to leave the audience 'sitting on the edge of their seat' and in some cases cause them to scream in terror, or their heart rate may increase, and this is called the Visceral Effect, which is the affect that the suspense will have on our physical bodies.
Suspense can also be created through the False Plateau, which lulls the audience into a falso sense of security, for example in the clip of Jaws when the children were caught swimming with sahrk fins on their back, the audience were made to think that everybody was safe however they weren't as the real shark was still roaming around looking for it's prey.