A thriller is a fictional work combining action and elements of mystery as well as romance on occasion. The term is closely related to "Suspense", as in suspense movie or suspense story.The thriller's audience is able to experience what Alfred Hitchcock, the master of the cinematic thriller, once termed "Beneficial shocks".
A modern subgenre is the technothriller, some of the first bestselling examples by Tom Clancy. They have a heavy emphasis on technology, but it is present or near-term technology or plausible variants, so it is not quite science fiction. A good technothriller allows a reader expert in the technology to suspend belief; a bad one can have the reader throwing the book down in disgust, saying "submarines don't do that." Technothrillers may have romance, but it is not a requirement; some argue the love interest is the technogy.