Computation 5926 225829173 2008-07-15T16:19:40Z Epbr123 1395162 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]] {{Comp-sci-stub}} [[ar:تحسيب]] [[he:חישוב (מדעי המחשב)]] [[hr:Računanje]] [[nl:Theoretische informatica]] [[pt:Computação]] [[su:Komputasi]] [[th:การคำนวณ]]