Digital is a term referring to a method of recording and reading data often contrasted with the analog. The root of the term is digit, so the digital is typically associated with numbers. Digital commonly refers to data or information organized and produced through a coding system, most frequently equated with the binary code which is the numerical language of computers based on a system of ones and zeros. Other examples of digital coding systems include Deoxyribonucleic acid (DNA), with its sequences of adenine (abbreviated A), cytosine (C), guanine (G) and thymine (T) that compose the information for particular biological arrangements and functions, and Morse code, based on a system of short and long sounds called dots and dashes. The distinction between analog and digital traces back to the works of John von Neumann and Gregory Bateson. (1) Von Neumann’s conceptualization occurs in a posthumously published book entitled The Computer and the Brain (1958). (2) Bateson’s distinction draws from his works such as Steps to an Ecology of Mind (1972) and Mind and Nature (1979). (3) For these theorists, analog data refers to continuous forms of data that work by transferring this data from an input stream to an output stream. For example, a phonograph is an analog system since the vibrations produced from the groove of the record (the input stream) are transferred into a loud speaker for their projection (output stream). The phonograph, like all analog media, works by a continuous transfer; the root of the term is analogy since the input stream is similar to the output stream (similar in the sense that the coding of the information remains the same). As the dictionary.com definition reads, “of or pertaining to a mechanism that represents data by measurement of a continuous physical variable, as voltage or pressure.” In contrast, digital media works via discrete units rather than continuous units and via translation rather than transfer. In other words, digital media are composed from a series of discrete units (dots and slashes or ones and zeroes) whose arrangement dictates the output based on the properties of the code. This is a process of translation since the original input is translated into digital code for processing. So, to continue with the music example, with digital music sound vibrations are translated into binary code which simulates those sound vibrations again upon output through a speaker.
According to Lev Manovich, the digital is distinguished by the characteristics of numerical representation, modularity, and automation (4). Numerical representation means that the data is translated into a series of discrete, quantified units. This ability to be numerically represented entails two consequences. First, a digital media object can be described formally or mathematically. Second, a new media object is subject to algorithmic manipulation (is programmable). Modularity refers to the fractal structure of the digital, which means that each element – sound, shape,etc. – is represented as discrete sample (pixels, voxels, scripts). This modularity allows infinite combination & permutation of the elements. Finally, automation means that the code can operate independently when constructed, allowing an automatic ability to manipulate and construct media and representations. Search engines and software techniques such as Photoshop’s filters and object generators illustrate this principle of automation.

(1)
A Companion to Digital Literary Studies, ed. Susan Schriebman and Ray Siemens. Oxford: Blackwell, 2008. http://www.digitalhumanities.org/companionDLS/
(2)
von Neumann, John (1958). The Computer and the Brain. New Haven: Yale University Press.
(3)
Bateson, Gregory (1972). Steps to an Ecology of Mind: Collected Essays in Anthropology, Psychiatry, Evolution, and Epistemology. San Francisco: Chandler.
Bateson, G. (1979). Mind and Nature: A Necessary Unity (Advances in Systems Theory, Complexity, and the Human Sciences). Hampton Press.
(4)
Manovich, Lev. The Language of New Media (Cambridge: MIT Press, 2001).