Suspension of disbelief is a willingness of a reader or viewer to suspend their critical faculties in order to "go along for the ride." The phrase was coined by Samuel Taylor Coleridge in his Biographia Literaria (pub. 1817), but the concept was certainly recognised by Shakespeare, who refers to it in the Prologue to Henry V: "make imaginary puissance...'tis your thoughts that now must deck our kings...turning th'accomplishment of many years into an hourglass...." The audience accepts limitations in the story being presented, sacrificing realism (and occasionally logic and believability) for the sake of enjoyment.
Suspension of disbelief is an essential component in live theatre.
It is an essential ingredient in the enjoyment of many B-grade science fiction films and TV series such as Doctor Who, when the audience willingly ignores low-budget "cheesy" props, plot holes, and poor acting in order to engage fully in the enjoyable and outrageous story.
As budgets have risen and special effects have become more and more lifelike, audiences have become less inclined to engage in suspension of disbelief. It is not uncommon for movie-going audiences to compare modern-day Hollywood blockbusters to movies made several decades ago and pronounce the former superior because the computer-generated special effects are more impressive than the effects used in the past, rather than accepting that at the time these movies were made such techniques were not available. A similar attitude applies to colour vs black and white films.