Web search engines work by storing information about many web pages, which they retrieve from the page's HTML. These pages are retrieved by a Web crawler (sometimes also known as a spider) — an automated Web browser which follows every link on the site. The site owner can make exclusions by using robots.txt. The contents of each page are then analyzed to determine how it should be indexed (for example, words can be extracted from the titles, page content, headings, or special fields called meta tags). Data about web pages are stored in an index database for use in later queries. A query from a user can be a single word. The index helps find information relating to the query as quickly as possible.
A web search engine is a software system that is designed to search for information on the World Wide Web. The search results are generally presented in a line of results often referred to as search engine results pages (SERPs). The information may be a specialist in web pages, images, information and other types of files. Some search engines also mine data available in databases or open directories. Unlike web directories, which are maintained only by human editors, search engines also maintain real-time information by running an algorithm on a web crawler.
Search Engine Watch has been covering search engines since June 1997 and has watched the industry evolve to its current state. Over time, many search engines have come and gone, as users have spoken with their keyboards.
During early development of the web, there was a list of webservers edited by Tim Berners-Lee and hosted on the CERN webserver. One historical snapshot from 1992 remains. As more webservers went online the central list could not keep up. On the NCSA site new servers were announced under the title "What's New!"
Most Web search engines are commercial ventures supported by advertising revenue and thus some of them allow advertisers to have their listings ranked higher in search results for a fee. Search engines that do not accept money for their search results make money by running search related ads alongside the regular search engine results. The search engines make money every time someone clicks on one of these ads.
If we see in the market of search engine, Google's worldwide market share peaked at 86.3% in April 2010. Yahoo!, Bing and other search engines are more popular in the US than in Europe. According to Hitwise, market share in the USA for October 2011 was Google 65.38%, Bing-powered (Bing and Yahoo!) 28.62%, and the remaining 66 search engines 6%. However, an Experian Hit wise report released in August 2011 gave the "success rate" of searches sampled in July. Over 80 percent of
Yahoo! and Bing searches resulted in the users visiting a web site, while Google's rate was just under 68 percent. In the People's Republic of China, Baidu held a 61.6% market share for web search in July 2009. In Russian Federation, Yandex holds around 60% of the market share as of April 2012.
Major Search Engines :
Google
Google was founded by Larry Page and Sergey Brin while they were Ph.D. students at Stanford University. Together they own about 16 percent of its shares. Google is an American multinational corporation specializing in Internet-related services and products. These include search, cloud computing, software and online advertising technologies. Most of its profits derive from AdWords.
They incorporated Google as a privately held company on September 4, 1998. An initial public offering followed on August 19, 2004. Its mission statement from the outset was "to organize the world's information and make it universally accessible and useful", and its unofficial slogan was "Don't be evil". In 2006 Google moved to headquarters in Mountain View, California.
The corporation has been estimated to run more than one million servers in data centers around the world and to process over one billion search requests and about twenty-four petabytes of user-generated data each day. In December 2012 Alexa listed google.com as the most visited website in the world. Numerous Google sites in other languages figure in the top one hundred, as do several other Google-owned sites such as YouTube and Blogger. Google ranks second in the BrandZ brand equity database. Its market dominance has led to criticism over issues including copyright, censorship, and privacy.
Yahoo
In January 1994, Yang and Filo were electrical engineering graduate students at Stanford University when they created a website named "Jerry's guide to the world wide web". David and Jerry's Guide to the World Wide Web was a directory of other websites, organized in a hierarchy, as opposed to a searchable index of pages. In March 1994, "David and Jerry's Guide to the World Wide Web" was renamed "Yahoo!" The "yahoo.com" domain was created on January 18, 1995.
Yahoo! was founded by Jerry Yang and David Filo in January 1994 and was incorporated on March 1, 1995. On July 16, 2012, former Google executive Marissa Mayer was named as Yahoo! CEO and President, effective July 17. Yahoo! Inc. is an American multinational internet corporation headquartered in Sunnyvale, California. It is widely known for its web portal, search engine Yahoo! Search, and related services, including Yahoo! Directory, Yahoo! Mail, Yahoo! News, Yahoo! Finance, Yahoo! Groups, Yahoo! Answers, advertising, online mapping, video sharing, fantasy sports and its social media website. It is one of the most popular sites in the United States. According to news sources, roughly 700 million people visit Yahoo! websites every month. Yahoo! itself claims it attracts "more than half a billion consumers every month in more than 30 languages."
As of January 2010, Yahoo! held the world's largest market share in online display advertising. JP Morgan put the company’s US market share for display ads at 17%, well ahead of No. 2 Microsoft at 11% and AOL at 7%. In 2011, Yahoo lost the top spot to Facebook.
Bing
Bing (known previously as Live Search, Windows Live Search, and MSN Search) is a web search engine (advertised as a "decision engine") from Microsoft.
Bing was unveiled by Microsoft CEO Steve Ballmer on May 28, 2009 at the All Things Digital conference in San Diego for release on June 1. Notable changes include the listing of search suggestions while queries are entered and a list of related searches (called "Explore pane") based on semantic technology from Powerset which Microsoft purchased in 2008.
On July 29, 2009, Microsoft and Yahoo! announced a deal in which Bing would power Yahoo! Search. All Yahoo! Search global customers and partners are expected to have made the transition by early 2012. In October 2011, Bing announced it was working on new back-end search infrastructure, with the goal of delivering faster and slightly more relevant search results for users. Known as "Tiger", the new index-serving technology has been incorporated into Bing globally, since August 2011. In May 2012, Bing announced another redesign of its search engine that includes "Sidebar", a social feature that searches users' social networks for information relevant to the search query.
MSN Search was a search engine by Microsoft that consisted of a search engine, index, and web crawler. MSN Search first launched in the third quarter of 1998 and used search results from Inktomi. In early 1999, MSN Search launched a version which displayed listings from Looksmart blended with results from Inktomi except for a short time in 1999 when results from AltaVista were used instead. Since then Microsoft upgraded MSN Search to provide its own self-built search engine results, the index of which was updated weekly and sometimes daily. The upgrade started as a beta program in November 2004, and came out of beta in February 2005. Image search was powered by a third party, Picsearch. The service also started providing its search results to other search engine portals in an effort to better compete in the market.