Before the introduction of digital production, series of still images were recorded on a strip of chemically sensitized celluloid (photographic film stock), usually at the rate of 24 frames per second. The images are transmitted through a movie projector at the same rate as they were recorded, with a Geneva drive ensuring that each frame remains still during its short projection time. A rotating shutter causes stroboscopic intervals of darkness, but the viewer does not notice the interruptions due to flicker fusion. The apparent motion on the screen is the result of the fact that the visual sense cannot discern the individual images at high speeds, so the impressions of the images blend with the dark intervals and are thus linked together to produce the illusion of one moving image. An analogous optical soundtrack (a graphic recording of the spoken words, music and other sounds) runs along a portion of the film exclusively reserved for it, and was not projected.
Many other terms exist for an individual motion-picture, including "picture", "picture show", "moving picture", "photoplay", and "flick". The most common term in the United States is "movie", while in Europe "film" is preferred. Archaic terms include "animated pictures" and "animated photography".
Common terms for the field in general include "the big screen", "the silver screen", "the movies", and "cinema"; the last of these is commonly used, as an overarching term, in scholarly texts and critical essays. In early years, the word "sheet" was sometimes used instead of "screen".
Émile Reynaud already mentioned the possibility of projecting the images of the Praxinoscope in his 1877 patent application. He presented a praxinoscope projection device at the Société française de photographie on 4 June 1880, but did not market his praxinoscope a projection before 1882. He then further developed the device into the Théâtre Optique which could project longer sequences with separate backgrounds, patented in 1888. He created several movies for the machine by painting images on hundreds of gelatin plates that were mounted into cardboard frames and attached to a cloth band. From 28 October 1892 to March 1900 Reynaud gave over 12,800 shows to a total of over 500,000 visitors at the Musée Grévin in Paris.
In the 1920s, the development of electronic sound recording technologies made it practical to incorporate a soundtrack of speech, music and sound effects synchronized with the action on the screen. The resulting sound films were initially distinguished from the usual silent "moving pictures" or "movies" by calling them "talking pictures" or "talkies." The revolution they wrought was swift. By 1930, silent film was practically extinct in the US and already being referred to as "the old medium."
Film is considered to have its own language. James Monaco wrote a classic text on film theory, titled "How to Read a Film," that addresses this. Director Ingmar Bergman famously said, "Andrei Tarkovsky for me is the greatest director, the one who invented a new language, true to the nature of film, as it captures life as a reflection, life as a dream." An example of the language is a sequence of back and forth images of one speaking actor's left profile, followed by another speaking actor's right profile, then a repetition of this, which is a language understood by the audience to indicate a conversation. This describes another theory of film, the 180-degree rule, as a visual story-telling device with an ability to place a viewer in a context of being psychologically present through the use of visual composition and editing. The "Hollywood style" includes this narrative theory, due to the overwhelming practice of the rule by movie studios based in Hollywood, California, during film's classical era. Another example of cinematic language is having a shot that zooms in on the forehead of an actor with an expression of silent reflection that cuts to a shot of a younger actor who vaguely resembles the first actor, indicating that the first person is remembering a past self, an edit of compositions that causes a time transition.
If a movie can illuminate the lives of other people who share this planet with us and show us not only how different they are but, how even so, they share the same dreams and hurts, then it deserves to be called great.
The impact of a reviewer on a given film's box office performance is a matter of debate. Some observers claim that movie marketing in the 2000s is so intense, well-coordinated and well financed that reviewers cannot prevent a poorly written or filmed blockbuster from attaining market success. However, the cataclysmic failure of some heavily promoted films which were harshly reviewed, as well as the unexpected success of critically praised independent films indicates that extreme critical reactions can have considerable influence. Other observers note that positive film reviews have been shown to spark interest in little-known films. Conversely, there have been several films in which film companies have so little confidence that they refuse to give reviewers an advanced viewing to avoid widespread panning of the film. However, this usually backfires, as reviewers are wise to the tactic and warn the public that the film may not be worth seeing and the films often do poorly as a result. Journalist film critics are sometimes called film reviewers. Critics who take a more academic approach to films, through publishing in film journals and writing books about films using film theory or film studies approaches, study how film and filming techniques work, and what effect they have on people. Rather than having their reviews published in newspapers or appearing on television, their articles are published in scholarly journals or up-market magazines. They also tend to be affiliated with colleges or universities as professors or instructors.
In the United States, much of the film industry is centered around Hollywood, California. Other regional centers exist in many parts of the world, such as Mumbai-centered Bollywood, the Indian film industry's Hindi cinema which produces the largest number of films in the world. Though the expense involved in making films has led cinema production to concentrate under the auspices of movie studios, recent advances in affordable film making equipment have allowed independent film productions to flourish.
Profit is a key force in the industry, due to the costly and risky nature of filmmaking; many films have large cost overruns, an example being Kevin Costner's Waterworld. Yet many filmmakers strive to create works of lasting social significance. The Academy Awards (also known as "the Oscars") are the most prominent film awards in the United States, providing recognition each year to films, based on their artistic merits. There is also a large industry for educational and instructional films made in lieu of or in addition to lectures and texts. Revenue in the industry is sometimes volatile due to the reliance on blockbuster films released in movie theaters. The rise of alternative home entertainment has raised questions about the future of the cinema industry, and Hollywood employment has become less reliable, particularly for medium and low-budget films.
Derivative academic fields of study may both interact with and develop independently of filmmaking, as in film theory and analysis. Fields of academic study have been created that are derivative or dependent on the existence of film, such as film criticism, film history, divisions of film propaganda in authoritarian governments, or psychological on subliminal effects (e.g., of a flashing soda can during a screening). These fields may further create derivative fields, such as a movie review section in a newspaper or a television guide. Sub-industries can spin off from film, such as popcorn makers, and film-related toys (e.g., Star Wars figures). Sub-industries of pre-existing industries may deal specifically with film, such as product placement and other advertising within films.
The terminology used for describing motion pictures varies considerably between British and American English. In British usage, the name of the medium is "film". The word "movie" is understood but seldom used. Additionally, "the pictures" (plural) is used semi-frequently to refer to the place where movies are exhibited, while in American English this may be called "the movies", but it is becoming outdated. In other countries, the place where movies are exhibited may be called a cinema or movie theatre. By contrast, in the United States, "movie" is the predominant form. Although the words "film" and "movie" are sometimes used interchangeably, "film" is more often used when considering artistic, theoretical, or technical aspects. The term "movies" more often refers to entertainment or commercial aspects, as where to go for fun evening on a date. For example, a book titled "How to Understand a Film" would probably be about the aesthetics or theory of film, while a book entitled "Let's Go to the Movies" would probably be about the history of entertaining movies and blockbusters.
Further terminology is used to distinguish various forms and media used in the film industry. "Motion pictures" and "moving pictures" are frequently used terms for film and movie productions specifically intended for theatrical exhibition, such as, for instance, Star Wars. "DVD" and "videotape" are video formats that can reproduce a photochemical film. A reproduction based on such is called a "transfer." After the advent of theatrical film as an industry, the television industry began using videotape as a recording medium. For many decades, tape was solely an analog medium onto which moving images could be either recorded or transferred. "Film" and "filming" refer to the photochemical medium that chemically records a visual image and the act of recording respectively. However, the act of shooting images with other visual media, such as with a digital camera, is still called "filming" and the resulting works often called "films" as interchangeable to "movies," despite not being shot on film. "Silent films" need not be utterly silent, but are films and movies without an audible dialogue, including those that have a musical accompaniment. The word, "Talkies," refers to the earliest sound films created to have audible dialogue recorded for playback along with the film, regardless of a musical accompaniment. "Cinema" either broadly encompasses both films and movies, or it is roughly synonymous with film and theatrical exhibition, and both are capitalized when referring to a category of art. The "silver screen" refers to the projection screen used to exhibit films and, by extension, is also used as a metonym for the entire film industry.