Search Engine, software program that helps users find information stored on a personal computer, or a network of computers, such as the Internet. A user enters search terms, typically by typing a keyword or phrase, and the search engine retrieves a list of World Wide Web (WWW) sites, personal computer files, or documents, either by scanning the content stored on the computers or computer networks being searched or by parsing (analyzing) an index of their stored data.
Search engines are most often used to find pages, files, news, images, and other data on the Web. Some of the most popular Web search engines include Google Inc., Microsoft Network (MSN) Search, and Yahoo! Inc. Each can be accessed from any Web browser, and each can be used for free. (Encarta Encyclopedia is published by the Microsoft Corporation.) These engines operate by building—and regularly updating—an enormous index of Web pages and files. This is done with the help of a Web crawler, or spider, a kind of automated browser that perpetually trolls the Web, retrieving each page it finds. Pages are then indexed according to the words they contain, with special treatment given to words in titles and other headers. When a user inputs a query, the search engine then scans the index and retrieves a list of pages that seem to best fit what the user is looking for. Search engines often return results in fractions of a second.
Generally, when an engine displays a list of results, pages are ranked according to how many other sites link to those pages. The assumption is that the more useful a site is, the more often other sites will send users to it. Google pioneered this technique in the late 1990s with a technology called PageRank. But this is not the only way of ranking results. Dozens of other criteria are used, and these will vary from engine to engine.
Many times, search results will also include what are called sponsored links, links that are ranked high in the search results or are prominently displayed because third-party companies pay a fee to the search engine. More often than not, sponsored links are labeled as such, but inexperienced Internet users often have trouble distinguishing between sponsored pages and unsponsored results. Sponsored links provide search engines with their primary source of revenue.
Take From: Microsoft ® Encarta ® 2008
Search engines are most often used to find pages, files, news, images, and other data on the Web. Some of the most popular Web search engines include Google Inc., Microsoft Network (MSN) Search, and Yahoo! Inc. Each can be accessed from any Web browser, and each can be used for free. (Encarta Encyclopedia is published by the Microsoft Corporation.) These engines operate by building—and regularly updating—an enormous index of Web pages and files. This is done with the help of a Web crawler, or spider, a kind of automated browser that perpetually trolls the Web, retrieving each page it finds. Pages are then indexed according to the words they contain, with special treatment given to words in titles and other headers. When a user inputs a query, the search engine then scans the index and retrieves a list of pages that seem to best fit what the user is looking for. Search engines often return results in fractions of a second.
Generally, when an engine displays a list of results, pages are ranked according to how many other sites link to those pages. The assumption is that the more useful a site is, the more often other sites will send users to it. Google pioneered this technique in the late 1990s with a technology called PageRank. But this is not the only way of ranking results. Dozens of other criteria are used, and these will vary from engine to engine.
Many times, search results will also include what are called sponsored links, links that are ranked high in the search results or are prominently displayed because third-party companies pay a fee to the search engine. More often than not, sponsored links are labeled as such, but inexperienced Internet users often have trouble distinguishing between sponsored pages and unsponsored results. Sponsored links provide search engines with their primary source of revenue.
Take From: Microsoft ® Encarta ® 2008
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