Suspense is a feeling of pleasurable fascination and excitement mixed with apprehension, tension, and anxiety developed from an unpredictable, mysterious, and rousing source of entertainment. The term most often refers to an audience's perceptions in a dramatic work. Suspense is not exclusive to fiction. It may operate whenever there is a perceived suspended drama or a chain of cause is left in doubt, with tension being a primary emotion felt as part of the situation.
In the kind of suspense described by film director Alfred Hitchcock, an audience experiences suspense when they expect something bad to happen and have (or believe they have) a superior perspective on events in the drama's hierarchy of knowledge, yet they are powerless to intervene to prevent it from happening. Films having a lot of suspense belong in the thriller genre.
In broader definition of suspense, this emotion arises when someone is aware of his lack of knowledge about the development of a meaningful event; thus, suspense is a combination of anticipation and uncertainty dealing with the obscurity of the future. In terms of narrative expectations, it may be contrasted with mystery or curiosity and surprise. Suspense could however be some small event in a person's life, such as a child anticipating an answer to a request they've made, such as, "May I get the kitty?" Therefore, suspense may be experienced to different degrees.