A search engine or search service is a program designed to help find information stored on a computer system such as the World Wide Web, inside a corporate or proprietary network or a personal computer. The search engine allows one to ask for content meeting specific criteria (typically those containing a given word or phrase) and retrieves a list of references that match those criteria. Search engines use regularly updated indexes to operate quickly and efficiently. Without further qualification, search engine usually refers to a Web search engine, which searches for information on the public Web. Other kinds of search engine are enterprise search engines, which search on intranets, personal search engines, which search individual personal computers, and mobile search engines. However, while different selection and relevance criteria may apply in different environments, the user will probably perceive little difference between operations in these. Some search engines also mine data available in newsgroups, large databases, or open directories like DMOZ.org. Unlike Web directories, which are maintained by human editors, search engines operate algorithmically. Most web sites which call themselves search engines are actually front ends to search engines owned by other companies.

History

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The very first tool used for searching on the Internet was Archie. (The name stands for "archive" without the "v", not the character from the 'Archie' comic book series). It was created in 1990 by Alan Emtage, a student at McGill University in Montreal. The program downloaded the directory listings of all the files located on public anonymous FTP (File Transfer Protocol) sites, creating a searchable database of filenames.

While Archie indexed computer files, Gopher indexed plain text documents. Gopher was created in 1991 by Mark McCahill at the University of Minnesota. (The program was named after the school's mascot). Because these were text files, most of the Gopher sites became Web sites after the creation of the World Wide Web.

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Wiley: All New Mathematics & Statistics Titles

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Stuart A. Klugman, Harry H. Panjer, Gordon E. Willmot Mon, 25 Aug 2008 04:00:00 -0000
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Oy Leuangthong, K. Daniel Khan, Clayton V. Deutsch Mon, 25 Aug 2008 04:00:00 -0000
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Roger Bilisoly Mon, 18 Aug 2008 04:00:00 -0000
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Loss Models: From Data to Decisions, 3rd Edition Set
Stuart A. Klugman, Harry H. Panjer, Gordon E. Willmot Fri, 15 Aug 2008 04:00:00 -0000
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Statistical Meta-Analysis with Applications
Joachim Hartung, Guido Knapp, Bimal K. Sinha Mon, 11 Aug 2008 04:00:00 -0000
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Fundamentals of Queueing Theory, 4th Edition
Donald Gross, John F. Shortle, James M. Thompson, Carl M. Harris Mon, 11 Aug 2008 04:00:00 -0000
  Fundamentals of Queueing Theory, 4th Edition presents the analytic modeling of queues using up-to-date examples and detailed coverage of the fundamentals of analytic modeling. A fresh emphasis on telecommunications enlivens the text, and spreadsheet programs for Excel and Quattro on the related Web site will help you understand the sensitivity of waiting-line systems to parameter and environmental changes. Read More...

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