A '''computer''' is a machine that is designed to perform a huge variety of information-processing tasks, depending on the program it has stored in its memory. Computers manipulate all data in the form of numbers, and encode all numbers in either [[binary|binary code]], which is base 2, or in the case of quantum computers, trinary ternary code which is base 3. Binary means that there can only be a 1 or a 0 in any data. This makes it possible to process data electronically, since one voltage can be used to represent a zero and another voltage for a one. Trinary Ternary systems are far more complicated, and still in development. The average personal or server computer uses binary.
==History==
[[Image:Babbage.jpg|right|thumb|200px|Contemporary (1800's) illustration of what Charles Babbage's Difference Engine might have looked like.]]
Babbage later designed a simpler and even more clever "Difference Engine Number 2", that was also not completed in his lifetime. But in 1991, the bicentennial of Babbage's birth, this computer was built in the British Science Museum, from Babbage's original plans. It operates flawlessly, though a few billion times more slowly than modern electronic computers. It is operated by turning a crank.
[[File:SSEM Replica.jpg|thumb|left|The Manchester Small-Scale Experimental Machine is considered the world's first stored-program computer, 1948.]]
The first computer comparable to the modern day computer, an electronic calculation machine, was the [[ENIAC]]. Built as a an artillery support machine, it was unveiled in early 1946.<ref>http://ftp.arl.army.mil/~mike/comphist/</ref>
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==Classifications==
===Mainframe===
[[File:NASAComputerRoom-1962.gif|250px|thumbnail|NASA's Mainfram computer (1962)]]
Mainframes were the first kind of computers, and always used to be the fastest option. They had the ability to process much more information at a faster rate than any other kind).<ref name="WorldBook01">The World Book Encyclopedia. 2001 ed. Vol. 4. Chicago: World Book, 2001. Print. Pages 908-94</ref> However, with the rapid advancement of technology in recent years, these have become obsolete. Since the modern laptop has more processing power than a mainframe of the 1990s, there is little point for the continued use of them. Mainframes also took up comparatively enormous amount of space, and consumed much more electricity than modern options. They have been since been replaced with the client-server architecture.<ref>"mainframe." Encyclopaedia Britannica. Britannica Academic. Encyclopædia Britannica Inc., 2016. Web. 31 May. 2016. <http://0-academic.eb.com.www.consuls.org/EBchecked/topic/358715/mainframe>.</ref>
===Client-server===
===Dedicated===
[[File:Playstation-SCPH-30000 vertical.jpg|150px|thumbnail|Dedicated [[PlayStation 2]] Computer]]
Dedicated computers are, as the name suggests, dedicated to a specific function. These can be almost anything from [[Video game]] consoles to a child's handheld toy. These are generally limited in functionality, since they are designed for their single task only.<ref name="WorldBook01">The World Book Encyclopedia. 2001 ed. Vol. 4. Chicago: World Book, 2001. Print. Pages 908-94</ref>
===Embedded===
Embedded computers are controllers built into the device they control. These are found in digital wrist watches, [[car]]s, landline telephones, and more.<ref name="WorldBook01">The World Book Encyclopedia. 2001 ed. Vol. 4. Chicago: World Book, 2001. Print. Pages 908-94</ref>
==Binary and ternary==Binary has always been used by computers and is somewhat familiar to most. However, some of the newest supercomputers now use ternary systems. ===Binary===Since the beginning of the digital computer, and even before this (when computers were mechanical), computers have always used "ones" and "zeros" for every calculation and operation. *The processor and circuitry operate using electrical pulses. A pulse is a "one" while a pause (no additional energy sent) is a "zero." *The [[Random-access memory|RAM]] switches are held in one position ("one") or released to the other ("zero")*Magnetic disks are magnetized to positive or negative, which represent "zero" and "one"*Optical disks have their foil melted by laser to show "zero" vs. "one"*Flash memory has microscopic toggle switches which are set to "one" or "zero"Every part of a binary computer uses theses "ones" and "zeros" for everything. ===Ternary===A new and evolving kind of computer breaks the "rules" of computer design entirely. Using properties of [[quantum mechanics]], these computers make use of alternate states of matter which can only exist very near [[absolute zero]]. Using these, a [[quantum computer]] can not only use ones and zeros, but also a sort of "both one and zero." Ternary processors must be kept incredibly cold, however. Due to this problem, as well as many other technical issues, that ternary computers are not commercially available. For now, these remain restricted to laboratories where space and liquid nitrogen are plentiful. However, it is believed that they may eventually replace binary computers.<ref>"quantum computer." Encyclopaedia Britannica. Britannica Academic. Encyclopædia Britannica Inc., 2016. Web. 31 May. 2016. <http://0-academic.eb.com.www.consuls.org/EBchecked/topic/746092/quantum-computer>.</ref>==See Alsoalso==
*[[Ada Lovelace]]
*[[Brain-computer interface]]
*[[Apple Computer]]
*[[Apple Computer|Apple]] [[iOS]] for [[iPhone]]-[[iPod]]-[[iPad]]
*[[Android (operating system)|Android]]
*[[BlackBerry OS|Blackberry]]
*[[Microsoft]] [[Windows Phone]] with [[Windows 8]]
*[[Acorn computers]]
*[[ZX Spectrum]]
==External Linkslinks==
*[http://www.dai.ed.ac.uk/homes/cam/fcomp.shtml Who Made the First Computer?]
*[http://www.cs.iastate.edu/jva/jva-obit.html John V. Atanasoff Dies at Age 91 Invented First Electronic Computer.] Washington Post Obituary.