Web search engine

A web search engine is designed to search for information on the World Wide Web.The information may be a specialist in web pages,images,information and over type of files.Some search engines also mine data available in databases or open directories.

History
The very first tool used for searching on the internet was Archie. The name stands for for 'archive' without the 'v'. It was created in 1990 by Alan Emtage ,Bill Heelan and J.Peter Deutsch, computer science students at McGill University in Montreal.Actually, Archie didi not index the contents of these sites since the amount of data was so limited it could be readily searched manually.
Although the first search engine was not prefect,many new search engine rise by years,such as the rise of Gopher(created in 1991 by Mark McCahill) led to two new search programs, Veronica and Jughead.
Watch the following timeline to be easy to understand.

Timeline (full list)
Year	Engine	Current status
1993	W3Catalog	Inactive
	Aliweb	Inactive
1994	WebCrawler	Active, Aggregator
	Go.com	Active, Yahoo Search
	Lycos	Active
1995	AltaVista	Active, Yahoo Search
	Daum	Active
	Magellan	Inactive
	Excite	Active
	SAPO	Active
	Yahoo!	Active, Launched as a directory
1996	Dogpile	Active, Aggregator
	Inktomi	Acquired by Yahoo!
	HotBot	Active (lycos.com)
	Ask Jeeves	Active (rebranded ask.com)
1997	Northern Light	Inactive
	Yandex	Active
1998	Google	Active
	MSN Search	Active as Bing
1999	AlltheWeb	Inactive (URL redirected to Yahoo!)
	GenieKnows	Active, rebranded Yellowee.com
	Naver	Active
	Teoma	Active
	Vivisimo	Inactive
2000	Baidu	Active
	Exalead	Inactive
2002	Inktomi	Acquired by Yahoo!
2003	Info.com	Active
2004	Yahoo! Search	Active, Launched own web search (see Yahoo! Directory, 1995)
	A9.com	Inactive
	Sogou	Active
2005	AOL Search	Active
	Ask.com	Active
	GoodSearch	Active
	SearchMe	Inactive
2006	wikiseek	Inactive
	Quaero	Active
	Ask.com	Active
	Live Search	Active as Bing, Launched as rebranded MSN Search
	ChaCha	Active
	Guruji.com	Active
2007	wikiseek	Inactive
	Sproose	Inactive
	Wikia Search	Inactive
	Blackle.com	Active
2008	Powerset	Inactive (redirects to Bing)
	Picollator	Inactive
	Viewzi	Inactive
	Boogami	Inactive
	LeapFish	Inactive
	Forestle	Inactive (redirects to Ecosia)
	VADLO	Active
	DuckDuckGo	Active, Aggregator
2009	Bing	Active, Launched as rebranded Live Search
	Yebol	Active
	Mugurdy	Inactive due to a lack of funding
	Goby	Active
2010	Blekko	Active
	Cuil	Inactive
	Yandex	Active, Launched global (English) search
	Yummly	Active
2011	Interred	Inactive
	Yandex	Active, Launched Turkey search
2012	Volunia	Active

Some of well known search engines

Goole Search is a web search engine owned by Google Inc,created on September 15,1997.Google Search is the most-used search engine on the World Wide Web,receiving several hundred million queries each day through its various services.

Yahoo!Search is a web search owned by Yahoo!Inc,created on March 1,1995.Originally,none of the actual web crawling and srorage of data was done by Yahoo! itself. In 2001 the searchable index was powered by Google until 2004, when Yahoo!Search became independent.

Bing is a web search 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.On July 29,2009, Microsoft and Yahoo! announced a deal in which Bing would power Yahoo!Search.

Reference: http://en.wikipedia.org/wiki/History_of_the_Internet#Search_engines

http://en.wikipedia.org/wiki/Yahoo!_Search

http://en.wikipedia.org/wiki/Google_Search

http://en.wikipedia.org/wiki/Bing_(search_engine)

Some of my feelings
Many search engines such as Google and Binf provide customized results based on the user's activity history.As a result,websites tend to show only information which agrees with the user's past viewpoint, effectively isolating the user in a bubble that tends to exclude contrary information.And i had heard something that some search engine will get pay from some websites and advance the websites on the page.Hence,the transparency of such search engines needs to be improved.