The word 'suspense' is used to describe a state of uncertainty. It denotes a condition of being anxious or 'in waiting'. The word suspense has both positive as well as negative connotations.
In a positive sense, it can be used to describe a sense of pleasant anticipation about something about to happen. It could be used to describe the way you feel in a situation where you know there is a pleasant surprise in store for you. It could also be used to describe a negative situation. For instance it can be used to describe the way you feel as you wait for some potential bad news.
The term suspense is also nowadays used to denote a genre in literature as well as films. In books the term is used to describe works of fiction that have the ending as ab unknown entity. In this sense it is different from the other genres.
it can be a state of mental uncertainty