Information in the natural world, received through the five senses, is analog. That means that it is infinitely variable. Digital A/V information, on the other hand, consists of discrete units of data that are placed so close together that the human senses perceive them as a continuous flow. Analog data, such as video recorded on tape, is transmitted as electronic signals of varying frequency or amplitude that are added to carrier waves of a given frequency. To make that information usable on a computer or a modern media player, analog-to-digital conversion translates an analog signal to a series of zeroes and ones, which represent, respectively, "negative" and "positive," "off" and "on," or "low" and "high." The opposite action, digital-to-analog conversion, recreates the analog signal for playback.
Digital video offers a number of advantages over analog video, including:
- Ease of sharing and storage.
- No degredation of data quality when copied.
- Easy and inexpensive copying.
- The capacity for multicasting.
Digital video technology can also incorporate analytical software for intelligent video, which enables capabilities such as video search, object tracking and intrusion detection.
Learn More About IT:
> Wikipedia has more background and information in its entry for digital video.
> HowStuffWorks explains digital data.
> Bruce Walls presents a simple explanation of digital video