Editing Digital data (section)

{{Merge from|Data (computer science)|discuss=Talk:Digital data#Proposed merge of Data (computer science) into Digital data|date=March 2025}}
{{Use dmy dates|date=January 2023}}
{{short description|Discrete, discontinuous representation of information}}
{{About|the concept in information theory and information systems|the electronics concept|Digital signal|other uses|Digital (disambiguation){{!}}Digital}}
[[File:Radiocontrolledclock.jpg|thumb|[[Digital clock]].  The time shown by the digits on the face at any instant is digital data.  The actual precise time is analog data. ]]

'''Digital data''', in [[information theory]] and [[information systems]], is information represented as a string of [[Discrete mathematics|discrete]] symbols, each of which can take on one of only a finite number of values from some [[alphabet (formal languages)|alphabet]], such as letters or digits. An example is a [[text document]], which consists of a string of [[alphanumeric character]]s. The most common form of digital data in modern information systems is ''[[binary data]]'', which is represented by a string of [[binary digit]]s (bits) each of which can have one of two values, either 0 or 1.

Digital data can be contrasted with ''analog data'', which is represented by a value from a [[continuous variable|continuous]] range of [[real number]]s. Analog data is transmitted by an [[analog signal]], which not only takes on continuous values but can vary continuously with time, a continuous [[real-valued function]] of time. An example is the air pressure variation in a [[sound wave]]. 

The word ''digital'' comes from the same source as the words [[digit (anatomy)|digit]] and ''digitus'' (the [[Latin]] word for ''finger''), as fingers are often used for counting. Mathematician [[George Stibitz]] of [[Bell Labs|Bell Telephone Laboratories]] used the word ''digital'' in reference to the fast electric pulses emitted by a device designed to aim and fire anti-aircraft guns in 1942.<ref>{{Cite book |last=Ceruzzi |first=Paul E |title=Computing: A Concise History |date=29 June 2012 |publisher=[[MIT Press]] |isbn=978-0-262-51767-6}}</ref> The term is most commonly used in [[computing]] and [[electronics]], especially where real-world information is converted to [[Binary numeral system|binary]] numeric form as in [[digital audio]] and [[digital photography]].