Digital video is an electronic representation of moving visual images (video) in the form of encoded digital data. This is in contrast to analog video, which represents moving visual images in the form of analog signals. Digital video comprises a series of digital images that are displayed in rapid succession. Analog and digital signals are used to transmit information, usually through electrical signals. In both technologies, information, like any audio or video, is transformed into electrical signals.
The difference between analog and digital technologies is that in analog technology, information is translated into electrical pulses of varying amplitude. In digital technology, information is translated in binary format (zero or one) where each bit is representative of two different amplitudes. Digital technology is fairly simple to define - a system that uses a digital signal simply represents information as discrete sampled values. An analog signal uses an electrical signal that varies continuously.
Both are means of encoding, and neither is the literal sound. A digital system gets its name because those discrete values are similar to counting (hence “digits”, like counting with your fingers), while an analog system uses an electrical signal that is analogous, although not literally, to the original one, since it varies in the way the pressure would do (in the case of sound).The main difference between digital and analog video is that digital video is made up of a series of discrete pixels, while analog video is continuous. Analog equipment also behaves in unique ways, since it is susceptible to climate variations, age, dirt and other characteristics, something that can be positive in some cases and negative in others, but which is more difficult to model in digital format. The choice of analog or digital circuits then depends on what is cheaper, more logical and on the desired sound and usability characteristics of a circuit. Digital video is a collection of digital images that are displayed rapidly in succession, while analog video uses analog signals to represent moving images.
Digital media is a relatively new term that refers to most recording media, including movies. Another difference between analog and digital is that analog technology is often more susceptible to noise than digital technology. Digital devices translate and reassemble data and, in the process, are more likely to lose quality compared to analog devices. For example, digital video can be transmitted over long distances without degradation, while analog signals tend to degrade with distance. As an expert in cinema who has been teaching for almost twenty years, I have experienced the shift from cinema and video to digital.
However, choosing between individual filters, worrying about the physical design of electronic instruments or recognizing that a digital or analog recording can be damaged - all these things still matter.