Search engine
The user inputs a query within a web browser or a mobile app, and the search results are often a list of hyperlinks, accompanied by textual summaries and images.The speed and accuracy of an engine's response to a query is based on a complex system of indexing that is continuously updated by automated web crawlers.[4] The memex was intended to give a user the capability to overcome the ever-increasing difficulty of locating information in ever-growing centralized indices of scientific work.The rise of Gopher (created in 1991 by Mark McCahill at the University of Minnesota) led to two new search programs, Veronica and Jughead.Oscar Nierstrasz at the University of Geneva wrote a series of Perl scripts that periodically mirrored these pages and rewrote them into a standard format.Aliweb did not use a web robot, but instead depended on being notified by website administrators of the existence at each site of an index file in a particular format.In 1996, Robin Li developed the RankDex site-scoring algorithm for search engines results page ranking[23][24][25] and received a US patent for the technology.[26] It was the first search engine that used hyperlinks to measure the quality of websites it was indexing,[27] predating the very similar algorithm patent filed by Google two years later in 1998.As of 2019,[update] active search engine crawlers include those of Google, Sogou, Baidu, Bing, Gigablast, Mojeek, DuckDuckGo and Yandex.After checking for robots.txt and either finding it or not, the spider sends certain information back to be indexed depending on many factors, such as the titles, page content, JavaScript, Cascading Style Sheets (CSS), headings, or its metadata in HTML meta tags.[36] Indexing means associating words and other definable tokens found on web pages to their domain names and HTML-based fields.[35] Some of the techniques for indexing, and caching are trade secrets, whereas web crawling is a straightforward process of visiting all sites on a systematic basis.Between visits by the spider, the cached version of the page (some or all the content needed to render it) stored in the search engine working memory is quickly sent to an inquirer.[35] Then the top search result item requires the lookup, reconstruction, and markup of the snippets showing the context of the keywords matched.There are two main types of search engine that have evolved: one is a system of predefined and hierarchically ordered keywords that humans have programmed extensively.[46][failed verification] Most countries' markets in the European Union are dominated by Google, except for the Czech Republic, where Seznam is a strong competitor.Although search engines are programmed to rank websites based on some combination of their popularity and relevancy, empirical studies indicate various political, economic, and social biases in the information they provide[48][49] and the underlying assumptions about the technology.[56] There has been concern raised that search engines such as Google and Bing provide customized results based on the user's activity history, leading to what has been termed echo chambers or filter bubbles by Eli Pariser in 2011.According to Eli Pariser users get less exposure to conflicting viewpoints and are isolated intellectually in their own informational bubble.More than usual safe search filters, these Islamic web portals categorizing websites into being either "halal" or "haram", based on interpretation of Sharia law.[62] While lack of investment and slow pace in technologies in the Muslim world has hindered progress and thwarted success of an Islamic search engine, targeting as the main consumers Islamic adherents, projects like Muxlim (a Muslim lifestyle site) received millions of dollars from investors like Rite Internet Ventures, and it also faltered.The first web search engine was Archie, created in 1990[67] by Alan Emtage, a student at McGill University in Montreal.Another Gopher search service, called Jughead, appeared a little later, probably for the sole purpose of rounding out the comic-strip triumvirate.Matthew Gray's Wanderer created quite a controversy at the time, partially because early versions of the software ran rampant through the Net and caused a noticeable netwide performance degradation.This leads to a relatively small database, which meant that users are less likely to search ALIWEB than one of the large bot-based sites.Their idea was to use statistical analysis of word relationships in order to provide more efficient searches through the large amount of information on the Internet.As the number of links grew and their pages began to receive thousands of hits a day, the team created ways to better organize the data.At Carnegie Mellon University during July 1994, Michael Mauldin, on leave from CMU, developed the Lycos search engine.Modern web search engines are highly intricate software systems that employ technology that has evolved over the years.The more prevalent search engines, such as Google and Yahoo!, utilize hundreds of thousands computers to process trillions of web pages in order to return fairly well-aimed results.
Search engine (disambiguation)suggestqueriessearch boxsoftware systemhyperlinksweb pagesthe Webinputsweb browsermobile appsearch resultsenginedistributed computingdata centersindexingweb crawlersdata miningdatabasesweb serversnot accessibleGoogle SearchYandexwebsitesmarketingoptimizationTimeline of web search enginesfull listW3CatalogALIWEBJumpStationWWW WormWebCrawlerGo.comInfoseekYahoo! SearchYahoo! DirectorySearch.chMagellanExciteMetaCrawlerAltaVistaRankDexDogpileHotBotInktomiAsk JeevesAOL Searchgoo.ne.jpNorthern LightGoogleIxquickMSN SearchAlltheWebGenieKnowsExaleadGigablastKartooInfo.comA9.comClustyMojeekSearchMeKidzSearchQuaeroSearch.comChaChaAsk.comLive SearchwikiseekSprooseWikia SearchBlackle.comPowersetPicollatorViewziBoogamiLeapFishForestleDuckDuckGoTinEyeScout (Goby)EcosiaStartpage.comBlekkoParsijooVoluniaEgerinSwisscowsKiddleBrave SearchYou.comVannevar BushAs We May ThinkThe Atlantic MonthlyLink analysisHyper SearchPageRankKnowbot Information ServiceArchieWorld Wide WebwebserversTim Berners-LeewebserverInternetAlan Emtagecomputer scienceMcGill UniversityMontreal, QuebecFile Transfer ProtocoldatabaseArchie Search EngineGopherMark McCahillUniversity of MinnesotaVeronicaJugheadArchie comic bookOscar NierstraszUniversity of Genevaweb robotWorld Wide Web Wandererwebsite administratorsJonathon Fletcherweb formweb page