Suspense is a technique used to foreshadows future events so the viewers/audience can get a small image of what may happen further on in the movie. The use of buliding up tension creates drama and leaves unanswered questions which makes the audience eager to know whats going to happen. The suspense created makes the audience sit on the edge of their seat. Some may scream in terror along with their heart rate increasing; this is called visceral effect, which affects on our physical body. A majority of times, the audience will know more than the characters on screen.
False Plateau is a technique used to lulls the audience into a false sense of security. An example is used in Jaws when the civilians think they see a shark, when it happened to be two kids playing a trick. So the suspense builded up for that moment but it was a false alarm, couple of minutes later the real event happens and everyone is shocked again.