what is WWW

8/8/2019 what is WWW

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y The World Wide Web is a system of interlinked hypertext documentscontained on the Internet.

y The WWW is a subset of thecomputers on the internet that connect

in a certain way, making theiraccessible to each other.


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WWW BACKGROUNDy 1989-1990 Tim Berners -Lee invents the World Wide Web at CERN

y Means for transferring text and graphics.y Client/Server data transfer protocol

y Communication via application levelprotocol.

y

Text mark up languagey Simple and easy to usey Requires a client application to render text.


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WWW History contdy 1994 Mark Andreesen invents MOSAIC at

National Center for Super Computing Applications (NCSA)

y First graphical browser.y Freely distributed.

y 1995 (approx.) Web traffic becomesdominant.

y E-commercey Web infrastructure companiesy

World Wide Web Consortium


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INTERNET AND WWWMany people use the terms Internet and World WideWeb interchangeably, but in fact the two terms are notsynonymous.

The Internet and the Web are two separate but relatedthings.


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HOW DOES WWW WORK?1. Starts with entering address of the website on the

web browser.2. Then browser requests all the web page from the web

server that host the site.3. The server transmits the data over the Internet to

your computer.4. web browser assembles and interprets the data,

displaying it on your computer screen


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WHAT DOES THE WWW USES? WWW uses the client -server model and an InternetProtocol (HTTP) for interaction between the computer onthe internet.


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KEY CONCEPTSIN WWWHYPERTEXT.HTTP.

UNIVERSA L RESOURCELOCATOR.HTML. WEB BROWSER.


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HYPERTEXTy Hypertext is text which is not constrained to be linear.y Text that is linked together in non - sequential form in

which user can browse through a related topics.y Text which contains links to other texts. The term was

coined by Ted Nelson around 1965.


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HTTPy A protocol to transfer hypertext requests andinformation between servers and browsers.

y HTTP is not constrained in principle to usingTCP/IP.

Request sent to Web server

Client Web Server

Response sent with files (one for eachWeb page, image, sound clip etc.)


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URLy The combination of the domain name and the

protocol name is called the uniform resource locator(UR L)

y E.g. http://www.yahoo.comy http is the protocoly www.yahoo.com is the domain nam e

y It also provides a means of locating the resource bydescribing its primary access mechanism.


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HTMLy HTML is a language that includes a set of tags attachedto text.

y These tags describe the relationship between text

elements.

y HTML documents describe web pages

y HTML documents are also called web pages


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WEB BROWSERy Is a software program that interprets the codinglanguage of the World Wide Web in graphic form,displaying the translation rather than the coding.

y Is a software that lets a user to view web pages andaccess files related to those documents.

y Notable browsers are Internet Explorer, NetscapeNavigator, Google Crome.


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F UNCTIONS O F WWWy Allows to create links from one piece of informationto another.

y Can incorporates references to sounds, graphics,movies etc.

y Understand other Internet Protocols, such as FTP,gopher and telnet.

y Enable a user to download information in variousformats.


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WWW is non-linear i.e-y You can jump from one link to another.

y You can directly go to a resource if you know the UR L.

y You can even jump to specific parts of a document.


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ADVANTAGES OF WWWy It is flexi le i r a izi & rese ti

i f r ati .y

It is - h ierarc h ical i at re.y It is a le t ha le & ersta a y

iffere t files & f r ats.y It is easy t se.y It is easy t avi ate.


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CONCLUSION


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Documents

what is WWW