WEB SEARCHING

WEB SEARCHING

A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier (URI) and may be a web page, image, video, or other piece of content. Hyperlinks present in resources enable users easily to navigate their browsers to related resources. A web browser can also be defined as an application software or program designed to enable users to access, retrieve and view documents and other resources on the Internet.

Although browsers are primarily intended to access the World Wide Web, they can also be used to access information provided by web servers inprivate networks or files in file systems.

The major web browsers are Internet Explorer, Firefox, Google Chrome, Safari, and Opera.

FUNCTION

The primary purpose of a web browser is to bring information resources to the user. This process begins when the user inputs a Uniform Resource Locator (URL), for example http://en.wikipedia.org/, into the browser. The prefix of the URL determines how the URL will be interpreted. The most commonly used kind of URI starts with http: and identifies a resource to be retrieved over the Hypertext Transfer Protocol (HTTP). Many browsers also support a variety of other prefixes, such as https: for HTTPS, ftp: for the File Transfer Protocol, and file: for local files. Prefixes that the web browser cannot directly handle are often handed off to another application entirely. For example, mailto: URIs are usually passed to the user's default e-mail application, and news: URIs are passed to the user's default newsgroup reader.

In the case of http, https, file, and others, once the resource has been retrieved the web browser will display it. HTML is passed to the browser's layout engine to be transformed from markup to an interactive document. Aside from HTML, web browsers can generally display any kind of content that can be part of a web page. Most browsers can display images, audio, video, and XML files, and often have plug-ins to support Flash applications and Java applets. Upon encountering a file of an unsupported type or a file that is set up to be downloaded rather than displayed, the browser prompts the user to save the file to disk.

Information resources may contain hyperlinks to other information resources. Each link contains the URI of a resource to go to. When a link is clicked, the browser navigates to the resource indicated by the link's target URI, and the process of bringing content to the user begins again.

Year	Web browsers	Internet users (in millions)
1991	WorldWideWeb (Nexus)	4
1992	ViolaWWW, Erwise, MidasWWW, MacWWW (Samba)	7
1993	Mosaic, Cello, Lynx 2.0, Arena, AMosaic 1.0	10
1994	IBM WebExplorer, Netscape Navigator, SlipKnot 1.0, MacWeb, IBrowse, Agora (Argo), Minuet	21
1995	Internet Explorer 1, Netscape Navigator 2.0, OmniWeb, UdiWWW, Internet Explorer 2, Grail	16-40
1996	Arachne 1.0, Internet Explorer 3.0, Netscape Navigator 3.0, Opera 2.0, PowerBrowser 1.5, Cyberdog, Amaya 0.9, AWeb, Voyager	36-74
1997	Internet Explorer 4.0, Netscape Navigator 4.0, Netscape Communicator 4.0, Opera 3.0, Amaya 1.0	70-119
1998	iCab, Mozilla	147-186
1999	Amaya 2.0, Mozilla M3, Internet Explorer 5.0	248-279
2000	Konqueror, Netscape 6, Opera 4, Opera 5, K-Meleon 0.2, Amaya 3.0, Amaya 4.0	361-393
2001	Internet Explorer 6, Galeon 1.0, Opera 6, Amaya 5.0	513-494
2002	Netscape 7, Mozilla 1.0, Phoenix 0.1, Links 2.0, Amaya 6.0, Amaya 7.0	587-673
2003	Opera 7, Safari 1.0, Epiphany 1.0, Amaya 8.0	719-783
2004	Firefox 1.0, Netscape Browser, OmniWeb 5.0	817-909
2005	Safari 2.0, Netscape Browser 8.0, Opera 8, Epiphany1.8, Amaya 9.0, AOL Explorer1.0, Maxthon 1.0, Shiira 1.0	1018-1021
2006	SeaMonkey 1.0, K-Meleon 1.0, Galeon 2.0, Camino 1.0, Firefox 2.0, Avant 11, iCab 3, Opera 9, Internet Explorer 7, Sputnik	1093-1146
2007	Maxthon 2.0, Netscape Navigator 9, NetSurf 1.0, Flock 1.0, Safari 3.0, Conkeror	1319-1357
2008	Konqueror 4, Safari 3.1, Opera 9.5, Firefox 3, Amaya 10.0, Flock 2, Chrome 1, Amaya 11.0	1574-1586
2009	Internet Explorer 8, Chrome 2 - 3, Safari 4, Opera 10, SeaMonkey 2, Camino 2, Firefox 3.5	1802
2010	K-Meleon 1.5.4, Firefox 3.6, Chrome 4 - 8, Opera 10.50, Safari 5, Opera 11	1971
2011	Chrome 9 - 15, Firefox 4 - 8, Internet Explorer 9, Maxthon 3.0, SeaMonkey 2.1 - 2.3, Opera 11.50, Safari 5.1	2095

SEARCH ENGINE

A web search engine is designed to search for information on the World Wide Web and FTP servers. The search results are generally presented in a list of results often referred to as SERPS, or "search engine results pages". The information may consist of 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.

Timeline (full list)
Year	Engine	Current status
1993	W3Catalog	Closed
	Aliweb	Closed
	JumpStation	Closed
1994	WebCrawler	Active, Aggregator
	Go.com	Active, Yahoo Search
	Lycos	Active
1995	AltaVista	Bought and operated by Yahoo!
	Daum	Active
	Magellan	Closed
	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 (ask.com, Jeeves went away)
1997	Northern Light	Closed
	Yandex	Active
1998	Google	Active
	MSN Search	Active as Bing
1999	AlltheWeb	Closed (URL redirected to Yahoo!)
	GenieKnows	Active, rebranded Yellowee.com
	Naver	Active
	Teoma	Active
	Vivisimo	Closed
2000	Baidu	Active
	Exalead	Acquired by Dassault Systèmes
2002	Inktomi	Acquired by Yahoo!
2003	Info.com	Active
2004	Yahoo! Search	Active, Launched own web search (see Yahoo! Directory, 1995)
	A9.com	Closed
	Sogou	Active
2005	AOL Search	Active
	Ask.com	Active
	GoodSearch	Active
	SearchMe	Closed
2006	wikiseek	Active
	Quaero	Active
	Ask.com	Active
	Live Search	Active as Bing, Launched as rebranded MSN Search
	ChaCha	Active
	Guruji.com	Active
2007	wikiseek	Closed
	Sproose	Closed
	Wikia Search	Closed
	Blackle.com	Active
2008	Powerset	Acquired by Microsoft
	Picollator	Closed
	Viewzi	Closed
	Boogami	Active
	LeapFish	Closed
	Forestle	Active
	VADLO	Active
	Duck Duck Go	Active, Aggregator
2009	Bing	Active, Launched as rebranded Live Search
	Yebol	Active
	Search2.net	Active
	Mugurdy	Closed due to a lack of funding
	Goby	Active
2010	Yandex	Active, Launched global (English) search
	Cuil	Closed
	Blekko	Active
	Yummly	Active
	Solusee	Active
2011
	Interred	Active