These are types of films known to encourage intense excitement, suspense, ultra-heightened expectation, uncertainty, anxiety, and nerve-wracking tension. Thriller and suspense films are virtually identical and interchangeable categorisations, with similar characteristics and features.
If the genre is to be defined strictly, a genuine thriller is a film that rentlessly pursues a single-minded goal to provide thrills and keep the audience cliff-hanging at the 'edge of their seats' as the plot builds towards a climax. The tension usually arises when the main character/s is placed in a menacing situation or mystery, or an escape or dangerous mission from which escape seems impossible. Life itself is threatened, usually because the principal character is unsuspecting or unknowingly involved in a dangerous or potentially deadly situation. Plots of thrillers involve characters which come into conflict with each other or with outside forces the menace is sometimes abstract or shadowy.