Introduction to the World Wide Web

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Introduction to the World Wide Web
B.K. DAS, National Informatics Centre
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What is the World Wide Web?

• The WWW gives you access to information on the
  Internet
• This information
• easy to read --formatted with text, graphics,
  sound and video
• contains hyperlinks--highlighted words that take
  you to other documents

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How Does the Web Work?

• Web is made up of computers that understand a
  common protocol (HTTP)
• HTTP allows computers to become part of the web
• These computers are called web servers

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What is HTTP?

• HyperText Transport Protocol
• Allows Web documents to be moved across the
  internet and retrieved by your computer.

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Common Protocols

• http Web Documents
• gopher Starts a gopher session
• news Reads UseNet newsgroups
• telnet Starts a telnet session
• ftp Starts an ftp session

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What is Hypertext?

• A non-linear way of organizing and browsing
  information.
• Jump to different pages by clicking on
  highlighted words.

Book (linear)
Web (hypertext)
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What is HTML?
ltOLgt
ltLIgt

• HyperText Markup Language
• Documents on the Web (web pages) are created with
  codes called HTML.
• HTML codes makes it possible to control the
  formatting of a web page.

ltULgt
ltFONTgt
ltA HREFgt
ltPgt
ltBRgt
ltBODYgt
ltHTMLgt
lt/Agt
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What is a Web Browser?

• Software that makes it easy to access information
  on the Internet.
• Browser software interprets the HTML codes in web
  pages so we can view them in a readable format.

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Browser Software

• Netscape
• Microsoft Internet Explorer
• Opera
• Mosaic
• Lynx

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What is a URL?

• Uniform Resource Locator
• Every page on the Web has a unique URL. The URL
  gives you the address of a page.

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Sample URL
http//www.ext.nodak.edu/miv/
Pathname location on server
Server where located
Protocol what it is
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Web Browser Tips

• URLs are case-sensitive
• Links are indicated by different colored text or
  change of mouse pointer
• Single-click links
• Click Reload or Refresh when page does not load
  properly

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Web-based Communication Tools

• Access without extra software
• Email sites
• http//www.hotmail.com
• Chat sites
• http//chat.yahoo.com
• Usenet News
• http//groups.google.com