In the fields of information science, communication, and industrial design, there is debate over the meaning of interactivity. In the "contingency view" of interactivity, there are three levels:

1. Noninteractive, when a message is not related to previous messages;
2. Reactive, when a message is related only to one immediately previous message; and
3. Interactive, when a message is related to a number of previous messages and to the relationship between them.

In filmmaking and video production, footage is the raw, unedited material as it had been originally filmed by movie camera or recorded by a video camera which usually must be edited to create a motion picture, video clip, television show or similar completed work. More loosely, footage can also refer to all sequences used in film and video editing, such as special effects and archive material (for special cases of this, see stock footage and B roll). Since the term originates in film, footage is only used for recorded images, such as film stock, videotapes or digitized clips – on live television, the signals from video cameras are called sources instead.
The origin of the term "footage" is that early 35 mm silent film has traditionally been measured in feet and frames; the fact that film was measured by length in cutting rooms, and that there are 16 frames (4-perf film format) in a foot of 35 mm film which roughly represented 1 second of silent film, made footage a natural unit of measure for film. The term then became used figuratively to describe moving image material of any kind.
Television footage, especially news footage, is often traded between television networks, but good footage usually commands a high price. The actual sum depends on duration, age, size of intended audience, duration of licensing and other factors. Amateur movie footage of current events can also often fetch a high price on the market – scenes shot inside the World Trade Center during the September 11, 2001 attacks were reportedly sold for US$45,000. Sometimes film projects will also sell or trade footage, usually second unit material not used in the final cut. For example, the end of the non-director's cut version of Blade Runner used landscape views that were originally shot for The Shining before the script was modified after shooting had finished.

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Animation is the rapid display of a sequence of images of 2-D or 3-D artwork or model positions in order to create an illusion of movement. The effect is an optical illusion of motion due to the phenomenon of persistence of vision, and can be created and demonstrated in several ways. The most common method of presenting animation is as a motion picture or video program, although there are other methods.

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Images may be two-dimensional, such as a photograph, screen display, and as well as a three-dimensional, such as a statue or hologram. They may be captured by optical devices—such as cameras, mirrors, lenses, telescopes, microscopes, etc. and natural objects and phenomena, such as the human eye or water surfaces.
The word image is also used in the broader sense of any two-dimensional figure such as a map, a graph, a pie chart, or an abstract painting. In this wider sense, images can also be rendered manually, such as by drawing, painting, carving, rendered automatically by printing or computer graphics technology, or developed by a combination of methods, especially in a pseudo-photograph.
A volatile image is one that exists only for a short period of time. This may be a reflection of an object by a mirror, a projection of a camera obscura, or a scene displayed on a cathode ray tube. A fixed image, also called a hard copy, is one that has been recorded on a material object, such as paper or textile by photography or digital processes.
A mental image exists in an individual's mind: something one remembers or imagines. The subject of an image need not be real; it may be an abstract concept, such as a graph, function, or "imaginary" entity. For example, Sigmund Freud claimed to have dreamed purely in aural-images of dialogs. The development of synthetic acoustic technologies and the creation of sound art have led to a consideration of the possibilities of a sound-image made up of irreducible phonic substance beyond linguistic or musicological analysis.
A still image is a single static image, as distinguished from a kinetic image (see below). This phrase is used in photography, visual media and the computer industry to emphasize that one is not talking about movies, or in very precise or pedantic technical writing such as a standard.
A film still is a photograph taken on the set of a movie or television program during production, used for promotional purposes.
There are many sayings about images. Such as "A picture is worth a thousand words.", as we know is not literally true.

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Sound recording and reproduction is an electrical or mechanical inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording technology are analog recording and digital recording. Acoustic analog recording is achieved by a small microphone diaphragm that can detect changes in atmospheric pressure (acoustic sound waves) and record them as a graphic representation of the sound waves on a medium such as a phonograph (in which a stylus senses grooves on a record). In magnetic tape recording, the sound waves vibrate the microphone diaphragm and are converted into a varying electric current, which is then converted to a varying magnetic field by an electromagnet, which makes a representation of the sound as magnetized areas on a plastic tape with a magnetic coating on it. Analog sound reproduction is the reverse process, with a bigger loudspeaker diaphragm causing changes to atmospheric pressure to form acoustic sound waves. Electronically generated sound waves may also be recorded directly from devices such as an electric guitar pickup or a synthesizer, without the use of acoustics in the recording process other than the need for musicians to hear how well they are playing during recording sessions.
Digital recording and reproduction converts the analog sound signal picked up by the microphone to a digital form by a process of digitization, allowing it to be stored and transmitted by a wider variety of media. Digital recording stores audio as a series of binary numbers representing samples of the amplitude of the audio signal at equal time intervals, at a sample rate high enough to convey all sounds capable of being heard. Digital recordings are considered higher quality than analog recordings not necessarily because they have higher fidelity (wider frequency response or dynamic range), but because the digital format can prevent much loss of quality found in analog recording due to noise and electromagnetic interference in playback, and mechanical deterioration or damage to the storage medium. A digital audio signal must be reconverted to analog form during playback before it is applied to a loudspeaker or earphones.

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Writing is the representation of language in a textual medium through the use of a set of signs or symbols (known as a writing system). It is distinguished from illustration, such as cave drawing and painting, and non-symbolic preservation of language via non-textual media, such as magnetic tape audio.
Writing most likely began as a consequence of political expansion in ancient cultures, which needed reliable means for transmitting information, maintaining financial accounts, keeping historical records, and similar activities. Around the 4th millennium BC, the complexity of trade and administration outgrew the power of memory, and writing became a more dependable method of recording and presenting transactions in a permanent form. In both Ancient Egypt and Mesoamerica writing may have evolved through calendrics and a political necessity for recording historical and environmental events.

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