Computation
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Reverted edits by [[Special:Contributions/OrgasGirl|OrgasGirl]] to last version by 130.243.88.35 (using [[WP:HG|Huggle]])
'''Computation''' is a general term for any type of [[information processing]]. This includes phenomena ranging from human thinking to calculations with a more narrow meaning. Computation is a process following a well-defined [[Model (abstract)|model]] that is understood and can be expressed in an [[algorithm]], [[Protocol (computing)|protocol]], [[network topology]], etc.
{{Wiktionary|computation}}
== Classes of computation ==
Computation can be classified by at least three orthogonal criteria: [[digital]] vs [[analog electronics|analog]], [[sequential]] vs [[parallel computation|parallel]] vs [[concurrent]], [[batch processing|batch]] vs [[interactive computation|interactive]].
In practice, digital computation is often used to simulate natural processes (for example,
[[Evolutionary computation]]), including those that are more naturally described by analog models of computation (for example, [[Artificial neural network]]). In this situation, it is important to distinguish between the mechanism of computation and the simulated model.
== Computations as a physical phenomenon ==
A computation can be seen as a purely physical phenomenon occurring inside a closed [[physical system]] called a [[computer]].
Examples of such physical systems include [[digital computer]]s, [[quantum computer]]s, [[DNA computer]]s, [[molecular computer]]s, [[analog computer]]s or [[wetware computer]]s.
This point of view is the one adopted by the branch of theoretical physics called the [[physics of computation]].
An even more radical point of view is the postulate of [[digital physics]] that the evolution of the universe itself is a computation - [[Pancomputationalism]].
Mathematical model of computation is a form of calculation, the procedure of calculating; determining something by mathematical or logical methods or problem solving that involves numbers or quantities.
== Mathematical models of computation ==
In the [[theory of computation]], a diversity of mathematical models of computers and their software are defined. A computation is considered as the evolution over discrete time epochs of such a model.
Typical mathematical models of computers are the following:
* [[Turing Machine]]
* [[Push-down automaton]]
* [[Finite state automaton]]
Typical mathematical models of computer software are the following:
* [[Formal grammar]]
* [[Recursive function]]
Different mathematical models of computers and their software can be classified according to their expressive power, see, for example, the [[Chomsky hierarchy]]. There are also other classifications of mathematical models of computers and their software .
== History ==
The word computation has an archaic meaning (from its [[Latin language|Latin]] etymological roots), but the word has come back in use with the arising of a new scientific discipline: [[computer science]].
== See also ==
{{portalpar | Computer Science | LampFlowchart.svg}}
* [[Computing]]
* [[Physical information]]
* [[Real computation]]
* [[Reversible computation]]
* [[Theory of computation]]
* [[Hypercomputation]]
* [[Pancomputationalism]]
[[Category:Theoretical computer science]]
[[Category:Recursion theory]]
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