Data (computer science): Difference between revisions

Revision as of 17:58, 20 November 2024

Revision as of 20:04, 20 November 2024

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In [[computer science]], '''data''' (treated as singular, plural, or as a [[mass noun]]) is any sequence of one or more [[symbol]]s; '''datum''' is a single symbol of data. Data requires [[Interpretation (logic)|interpretation]] to become [[information]]. ''[[Digital data]]'' is data that is represented using the [[binary number]] system of ones (1) and zeros (0), instead of [[analog signal|analog]] representation. In modern (post-1960) computer systems, all data is digital.

Data exists in three states: [[data at rest]], [[data in transit]] and [[data in use]]. Data within a computer, in most cases, [[Parallel communication|moves as parallel data]]. Data moving to or from a computer, in most cases, [[Serial communication|moves as serial data]]. Data sourced from an analog device, such as a temperature sensor, may be converted to digital using an [[analog-to-digital converter]]. Data representing [[Quantity|quantities]], characters, or symbols on which operations are performed by a [[computer]] are [[Data storage|stored]] and [[Record (computer science)|recorded]] on [[magnetic tape data storage|magnetic]], [[optical storage|optical]], electronic, or mechanical recording media, and [[Data communication|transmitted]] in the form of digital, electrical or optical signals.<ref>{{cite web|url=https://www.lexico.com/en/definition/data|title=Data|work=Lexico|access-date=14 January 2022|url-status=dead|archive-url=https://web.archive.org/web/20190623094330/https://www.lexico.com/en/definition/data |archive-date=2019-06-23 }}</ref> Data pass in and out of computers via [[peripheral|peripheral devices]].

Physical [[computer memory]] elements consist of an address and a byte/word of data storage. Digital data are often stored in [[Relational database#RDBMS|relational databases]], like [[table (database)|tables]] or SQL databases, and can generally be represented as abstract key/value pairs. Data can be organized in many different types of [[data structure]]s, including arrays, [[Graph (abstract data type)|graphs]], and [[Object (computer science)|objects]]. Data structures can store data of many different [[data type|types]], including [[Floating-point arithmetic|numbers]], [[string (computer science)|strings]] and even other [[Recursive data type|data structures]].

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===RAM===

* [[Random access memory]] (RAM) holds data that the CPU has direct access to. A CPU may only manipulate data within its [[processor register]]s or memory. This is as opposed to data storage, where the CPU must direct the transfer of data between the storage device (disk, tape...) and memory. RAM is an array of linear contiguous locations that a processor may read or write by providing an address for the read or write operation. The processor may operate on any ___location in memory at any time in any order. In RAM, the smallest element of data is the binary [[bit]]. The capabilities and limitations of accessing RAM are processor specific. In general [[Computer data storage|main memory]] is arranged as an array of [[Memory address|locations]] beginning at address 0 ([[hexadecimal]] 0). Each ___location can store usually 8 or 32 bits depending on the [[computer architecture]].

===Keys===