تقنية معلومات

"IT" redirects here. For other uses, see IT (توضيح).
"Infotech" redirects here. For the Indian company, see Cyient.
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المجالات والفروع ذات الصلة
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Information technology (IT) is the use of computers to store, retrieve, transmit, and manipulate data[1] or information. IT is typically used within the context of business operations as opposed to personal or entertainment technologies.[2] IT is considered to be a subset of information and communications technology (ICT). An information technology system (IT system) is generally an information system, a communications system, or, more specifically speaking, a computer system – including all hardware, software, and peripheral equipment – operated by a limited group of users.

Humans have been storing, retrieving, manipulating, and communicating information since the Sumerians in Mesopotamia developed writing in about 3000 BC.[3] However, the term information technology in its modern sense first appeared in a 1958 article published in the Harvard Business Review; authors Harold J. Leavitt and Thomas L. Whisler commented that "the new technology does not yet have a single established name. We shall call it information technology (IT)." Their definition consists of three categories: techniques for processing, the application of statistical and mathematical methods to decision-making, and the simulation of higher-order thinking through computer programs.[4]

The term is commonly used as a synonym for computers and computer networks, but it also encompasses other information distribution technologies such as television and telephones. Several products or services within an economy are associated with information technology, including computer hardware, software, electronics, semiconductors, internet, telecom equipment, and e-commerce.[5][أ]

Based on the storage and processing technologies employed, it is possible to distinguish four distinct phases of IT development: pre-mechanical (3000 BC – 1450 AD), mechanical (1450–1840), electromechanical (1840–1940), and electronic (1940–present).[3] This article focuses on the most recent period (electronic).

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History of computer technology

Zuse Z3 replica on display at Deutsches Museum in Munich. The Zuse Z3 is the first programmable computer.
المقالة الرئيسية: History of computing hardware

Devices have been used to aid computation for thousands of years, probably initially in the form of a tally stick.[7] The Antikythera mechanism, dating from about the beginning of the first century BC, is generally considered to be the earliest known mechanical analog computer, and the earliest known geared mechanism.[8] Comparable geared devices did not emerge in Europe until the 16th century, and it was not until 1645 that the first mechanical calculator capable of performing the four basic arithmetical operations was developed.[9]

Electronic computers, using either relays or valves, began to appear in the early 1940s. The electromechanical Zuse Z3, completed in 1941, was the world's first programmable computer, and by modern standards one of the first machines that could be considered a complete computing machine. Colossus, developed during the Second World War to decrypt German messages, was the first electronic digital computer. Although it was programmable, it was not general-purpose, being designed to perform only a single task. It also lacked the ability to store its program in memory; programming was carried out using plugs and switches to alter the internal wiring.[10] The first recognisably modern electronic digital stored-program computer was the Manchester Baby, which ran its first program on 21 June 1948.[11]

The development of transistors in the late 1940s at Bell Laboratories allowed a new generation of computers to be designed with greatly reduced power consumption. The first commercially available stored-program computer, the Ferranti Mark I, contained 4050 valves and had a power consumption of 25 kilowatts. By comparison, the first transistorized computer developed at the University of Manchester and operational by November 1953, consumed only 150 watts in its final version.[12]

Several later breakthroughs in semiconductor technology include the integrated circuit (IC) invented by Jack Kilby at Texas Instruments and Robert Noyce at Fairchild Semiconductor in 1959, the metal-oxide-semiconductor field-effect transistor (MOSFET) invented by Mohamed Atalla and Dawon Kahng at Bell Laboratories in 1959, and the microprocessor invented by Ted Hoff, Federico Faggin, Masatoshi Shima and Stanley Mazor at Intel in 1971. These important inventions led to the development of the personal computer (PC) in the 1970s, and the emergence of information and communications technology (ICT).[13]


Electronic data processing

المقالة الرئيسية: Electronic data processing

Data storage

Punched tapes were used in early computers to represent data.
المقالة الرئيسية: Data storage device

Early electronic computers such as Colossus made use of punched tape, a long strip of paper on which data was represented by a series of holes, a technology now obsolete.[14] Electronic data storage, which is used in modern computers, dates from World War II, when a form of delay line memory was developed to remove the clutter from radar signals, the first practical application of which was the mercury delay line.[15] The first random-access digital storage device was the Williams tube, based on a standard cathode ray tube,[16] but the information stored in it and delay line memory was volatile in that it had to be continuously refreshed, and thus was lost once power was removed. The earliest form of non-volatile computer storage was the magnetic drum, invented in 1932[17] and used in the Ferranti Mark 1, the world's first commercially available general-purpose electronic computer.[18]

IBM introduced the first hard disk drive in 1956, as a component of their 305 RAMAC computer system.[19]:6 Most digital data today is still stored magnetically on hard disks, or optically on media such as CD-ROMs.[20]:4–5 Until 2002 most information was stored on analog devices, but that year digital storage capacity exceeded analog for the first time. As of 2007 almost 94% of the data stored worldwide was held digitally:[21] 52% on hard disks, 28% on optical devices and 11% on digital magnetic tape. It has been estimated that the worldwide capacity to store information on electronic devices grew from less than 3 exabytes in 1986 to 295 exabytes in 2007,[22] doubling roughly every 3 years.[23]

Databases

المقالة الرئيسية: Database

Database Management Systems (DMS) emerged in the 1960s to address the problem of storing and retrieving large amounts of data accurately and quickly. An early such systems was IBM's Information Management System (IMS),[24] which is still widely deployed more than 50 years later.[25] IMS stores data hierarchically,[24] but in the 1970s Ted Codd proposed an alternative relational storage model based on set theory and predicate logic and the familiar concepts of tables, rows and columns. In 1981, the first commercially available relational database management system (RDBMS) was released by Oracle.[26]

All DMS consist of components, they allow the data they store to be accessed simultaneously by many users while maintaining its integrity.[27] All databases are common in one point that the structure of the data they contain is defined and stored separately from the data itself, in a database schema.[24]

In recent years, the extensible markup language (XML) has become a popular format for data representation. Although XML data can be stored in normal file systems, it is commonly held in relational databases to take advantage of their "robust implementation verified by years of both theoretical and practical effort".[28] As an evolution of the Standard Generalized Markup Language (SGML), XML's text-based structure offers the advantage of being both machine and human-readable.[29]

Data retrieval

The relational database model introduced a programming-language independent Structured Query Language (SQL), based on relational algebra.

The terms "data" and "information" are not synonymous. Anything stored is data, but it only becomes information when it is organized and presented meaningfully.[30]:1–9 Most of the world's digital data is unstructured, and stored in a variety of different physical formats[31][ب] even within a single organization. Data warehouses began to be developed in the 1980s to integrate these disparate stores. They typically contain data extracted from various sources, including external sources such as the Internet, organized in such a way as to facilitate decision support systems (DSS).[32]:4–6

Data transmission

Data transmission has three aspects: transmission, propagation, and reception.[33] It can be broadly categorized as broadcasting, in which information is transmitted unidirectionally downstream, or telecommunications, with bidirectional upstream and downstream channels.[22]

XML has been increasingly employed as a means of data interchange since the early 2000s,[34] particularly for machine-oriented interactions such as those involved in web-oriented protocols such as SOAP,[29] describing "data-in-transit rather than ... data-at-rest".[34]

Data manipulation

Hilbert and Lopez identify the exponential pace of technological change (a kind of Moore's law): machines' application-specific capacity to compute information per capita roughly doubled every 14 months between 1986 and 2007; the per capita capacity of the world's general-purpose computers doubled every 18 months during the same two decades; the global telecommunication capacity per capita doubled every 34 months; the world's storage capacity per capita required roughly 40 months to double (every 3 years); and per capita broadcast information has doubled every 12.3 years.[22]

Massive amounts of data are stored worldwide every day, but unless it can be analysed and presented effectively it essentially resides in what have been called data tombs: "data archives that are seldom visited".[35] To address that issue, the field of data mining – "the process of discovering interesting patterns and knowledge from large amounts of data"[36] – emerged in the late 1980s.[37]

Perspectives

Academic perspective

In an academic context, the Association for Computing Machinery defines IT as "undergraduate degree programs that prepare students to meet the computer technology needs of business, government, healthcare, schools, and other kinds of organizations .... IT specialists assume responsibility for selecting hardware and software products appropriate for an organization, integrating those products with organizational needs and infrastructure, and installing, customizing, and maintaining those applications for the organization’s computer users."[38]

Commercial and employment perspective

Companies in the information technology field are often discussed as a group as the "tech sector" or the "tech industry".[39][40][41]

Many companies now have IT departments for managing the computers, networks, and other technical areas of their businesses.

In a business context, the Information Technology Association of America has defined information technology as "the study, design, development, application, implementation, support or management of computer-based information systems".[42][صفحة مطلوبة] The responsibilities of those working in the field include network administration, software development and installation, and the planning and management of an organization's technology life cycle, by which hardware and software are maintained, upgraded and replaced.

  • U.S. Employment distribution of computer systems design and related services, 2011[43]

    U.S. Employment distribution of computer systems design and related services, 2011[43]

  • U.S. Employment in the computer systems and design related services industry, in thousands, 1990-2011[43]

    U.S. Employment in the computer systems and design related services industry, in thousands, 1990-2011[43]

  • U.S. Occupational growth and wages in computer systems design and related services, 2010-2020[43]

    U.S. Occupational growth and wages in computer systems design and related services, 2010-2020[43]

  • U.S. projected percent change in employment in selected occupations in computer systems design and related services, 2010-2020[43]

    U.S. projected percent change in employment in selected occupations in computer systems design and related services, 2010-2020[43]

  • U.S. projected average annual percent change in output and employment in selected industries, 2010-2020[43]

    U.S. projected average annual percent change in output and employment in selected industries, 2010-2020[43]


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Ethical perspectives

المقالة الرئيسية: Information ethics

The field of information ethics was established by mathematician Norbert Wiener in the 1940s.[44]:9 Some of the ethical issues associated with the use of information technology include:[45]:20–21

  • Breaches of copyright by those downloading files stored without the permission of the copyright holders
  • Employers monitoring their employees' emails and other Internet usage
  • Unsolicited emails
  • Hackers accessing online databases
  • Web sites installing cookies or spyware to monitor a user's online activities

See also

References

Notes

  1. ^ On the later more broad application of the term IT, Keary comments: "In its original application 'information technology' was appropriate to describe the convergence of technologies with application in the vast field of data storage, retrieval, processing, and dissemination. This useful conceptual term has since been converted to what purports to be of great use, but without the reinforcement of definition ... the term IT lacks substance when applied to the name of any function, discipline, or position."[6]
  2. ^ "Format" refers to the physical characteristics of the stored data such as its encoding scheme; "structure" describes the organisation of that data.

Citations

  1. ^ Daintith, John, ed. (2009), "IT", A Dictionary of Physics, Oxford University Press, ISBN 9780199233991, http://www.oxfordreference.com/views/ENTRY.html?subview=Main&entry=t83.e1592, retrieved on 1 August 2012  (يتطلب اشتراك)
  2. ^ "Free on-line dictionary of computing (FOLDOC)". Archived from the original on 15 أبريل 2013. Retrieved 9 فبراير 2013.
  3. ^ أ ب Butler, Jeremy G., A History of Information Technology and Systems, University of Arizona, http://www.tcf.ua.edu/AZ/ITHistoryOutline.htm, retrieved on 2 August 2012 
  4. ^ Leavitt, Harold J.; Whisler, Thomas L. (1958), "Management in the 1980s", Harvard Business Review 11, http://hbr.org/1958/11/management-in-the-1980s 
  5. ^ Chandler, Daniel; Munday, Rod (2011-02-10), "Information technology", A Dictionary of Media and Communication (first ed.), Oxford University Press, ISBN 978-0199568758, https://books.google.com/books?id=nLuJz-ZB828C&pg=PA211, retrieved on 1 August 2012, "Commonly a synonym for computers and computer networks but more broadly designating any technology that is used to generate, store, process, and/or distribute information electronically, including television and telephone." 
  6. ^ Ralston, Hemmendinger & Reilly (2000), p. 869
  7. ^ Schmandt-Besserat, Denise (1981), "Decipherment of the earliest tablets", Science 211 (4479): 283–85, doi:10.1126/science.211.4479.283, PMID 17748027, Bibcode: 1981Sci...211..283S 
  8. ^ Wright (2012), p. 279
  9. ^ Chaudhuri (2004), p. 3
  10. ^ Lavington (1980), p. 11
  11. ^ Enticknap, Nicholas (Summer 1998), "Computing's Golden Jubilee", Resurrection (20), ISSN 0958-7403, http://www.cs.man.ac.uk/CCS/res/res20.htm#d, retrieved on 19 April 2008 
  12. ^ Cooke-Yarborough, E. H. (June 1998), "Some early transistor applications in the UK", Engineering Science & Education Journal 7 (3): 100–106, doi:10.1049/esej:19980301, ISSN 0963-7346 
  13. ^ "Advanced information on the Nobel Prize in Physics 2000" (PDF). Nobel Prize. يونيو 2018. Retrieved 17 ديسمبر 2019.
  14. ^ Alavudeen & Venkateshwaran (2010), p. 178
  15. ^ Lavington (1998), p. 1
  16. ^ "Early computers at Manchester University", Resurrection 1 (4), Summer 1992, ISSN 0958-7403, http://www.cs.man.ac.uk/CCS/res/res04.htm#g, retrieved on 19 April 2008 
  17. ^ Universität Klagenfurt, ed., Magnetic drum, http://cs-exhibitions.uni-klu.ac.at/index.php?id=222, retrieved on 21 August 2011 
  18. ^ The Manchester Mark 1, University of Manchester, http://www.digital60.org/birth/manchestercomputers/mark1/manchester.html, retrieved on 24 January 2009 
  19. ^ Khurshudov, Andrei (2001), The Essential Guide to Computer Data Storage: From Floppy to DVD, Prentice Hall, ISBN 978-0-130-92739-2, https://archive.org/details/essentialguideto00andr 
  20. ^ Wang, Shan X.; Taratorin, Aleksandr Markovich (1999), Magnetic Information Storage Technology, Academic Press, ISBN 978-0-12-734570-3 
  21. ^ Wu, Suzanne, How Much Information Is There in the World?, University of Southern California, http://news.usc.edu/#!/article/29360/How-Much-Information-Is-There-in-the-World, retrieved on 10 September 2013 
  22. ^ أ ب ت Hilbert, Martin; López, Priscila (1 April 2011), "The World's Technological Capacity to Store, Communicate, and Compute Information", Science 332 (6025): 60–65, doi:10.1126/science.1200970, PMID 21310967, Bibcode: 2011Sci...332...60H, http://www.sciencemag.org/content/332/6025/60.full?sid=ef08b031-c911-46ae-9e9c-d675cc635c6d, retrieved on 10 September 2013 
  23. ^ "Americas events- Video animation on The World's Technological Capacity to Store, Communicate, and Compute Information from 1986 to 2010". The Economist. Archived from the original on 18 يناير 2012.
  24. ^ أ ب ت Ward & Dafoulas (2006), p. 2
  25. ^ Olofson, Carl W. (October 2009), A Platform for Enterprise Data Services, IDC, http://public.dhe.ibm.com/software/data/sw-library/ims/idc-power-of-ims.pdf, retrieved on 7 August 2012 
  26. ^ Ward & Dafoulas (2006), p. 3
  27. ^ Silberschatz, Abraham (2010). Database System Concepts (in الإنجليزية). McGraw-Hill Higher Education. ISBN 978-0-07-741800-7.
  28. ^ Pardede (2009), p. 2
  29. ^ أ ب Pardede (2009), p. 4
  30. ^ Kedar, Seema (2009). Database Management System (in الإنجليزية). Technical Publications. ISBN 9788184316049.
  31. ^ van der Aalst (2011), p. 2
  32. ^ Dyché, Jill (2000), Turning Data Into Information With Data Warehousing, Addison Wesley, ISBN 978-0-201-65780-7, https://archive.org/details/edataturningdata00dych 
  33. ^ Weik (2000), p. 361
  34. ^ أ ب Pardede (2009), p. xiii
  35. ^ Han, Kamber & Pei (2011), p. 5
  36. ^ Han, Kamber & Pei (2011), p. 8
  37. ^ Han, Kamber & Pei (2011), p. xxiii
  38. ^ The Joint Task Force for Computing Curricula 2005.Computing Curricula 2005: The Overview Report (pdf) Archived 21 أكتوبر 2014 at the Wayback Machine
  39. ^ "Technology Sector Snapshot". The New York Times. Archived from the original on 13 يناير 2017. Retrieved 12 يناير 2017.
  40. ^ "Our programmes, campaigns and partnerships". TechUK. Retrieved 12 يناير 2017.
  41. ^ "Cyberstates 2016". CompTIA. Retrieved 12 يناير 2017.
  42. ^ Proctor, K. Scott (2011), Optimizing and Assessing Information Technology: Improving Business Project Execution, John Wiley & Sons, ISBN 978-1-118-10263-3 
  43. ^ أ ب ت ث ج Lauren Csorny (9 أبريل 2013). "U.S. Careers in the growing field of information technology services : Beyond the Numbers: U.S. Bureau of Labor Statistics". bls.gov.
  44. ^ Bynum, Terrell Ward (2008), "Norbert Wiener and the Rise of Information Ethics", in van den Hoven, Jeroen; Weckert, John, Information Technology and Moral Philosophy, Cambridge University Press, ISBN 978-0-521-85549-5 
  45. ^ Reynolds, George (2009), Ethics in Information Technology, Cengage Learning, ISBN 978-0-538-74622-9 

Bibliography

  • Alavudeen, A.; Venkateshwaran, N. (2010), Computer Integrated Manufacturing, PHI Learning, ISBN 978-81-203-3345-1 
  • Chaudhuri, P. Pal (2004), Computer Organization and Design, PHI Learning, ISBN 978-81-203-1254-8 
  • Han, Jiawei; Kamber, Micheline; Pei, Jian (2011), Data Mining: Concepts and Techniques (3rd ed.), Morgan Kaufmann, ISBN 978-0-12-381479-1 
  • Lavington, Simon (1980), Early British Computers, Manchester University Press, ISBN 978-0-7190-0810-8 
  • Lavington, Simon (1998), A History of Manchester Computers (2nd ed.), The British Computer Society, ISBN 978-1-902505-01-5 
  • Pardede, Eric (2009), Open and Novel Issues in XML Database Applications, Information Science Reference, ISBN 978-1-60566-308-1 
  • Ralston, Anthony; Hemmendinger, David; Reilly, Edwin D., eds. (2000), Encyclopedia of Computer Science (4th ed.), Nature Publishing Group, ISBN 978-1-56159-248-7 
  • van der Aalst, Wil M. P. (2011), Process Mining: Discovery, Conformance and Enhancement of Business Processes, Springer, ISBN 978-3-642-19344-6 
  • Ward, Patricia; Dafoulas, George S. (2006), Database Management Systems, Cengage Learning EMEA, ISBN 978-1-84480-452-8 
  • Weik, Martin (2000), Computer Science and Communications Dictionary, 2, Springer, ISBN 978-0-7923-8425-0 
  • Wright, Michael T. (2012), "The Front Dial of the Antikythera Mechanism", in Koetsier, Teun; Ceccarelli, Marco, Explorations in the History of Machines and Mechanisms: Proceedings of HMM2012, Springer, pp. 279–292, ISBN 978-94-007-4131-7 

Further reading


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External links

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