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Internet and the World Wide Web

Internet and the World Wide Web. Lecture 11. Summary of Previous. Introduction to Telecommunications Basic Components of Communications Telecommunications Media Rate of data transfer Essential computer Network Terminologies Network Topology Classification of Computer Networks

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Internet and the World Wide Web

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  1. Internet and the World Wide Web Lecture 11

  2. Summary of Previous • Introduction to Telecommunications • Basic Components of Communications • Telecommunications Media • Rate of data transfer • Essential computer Network Terminologies • Network Topology • Classification of Computer Networks • Network Devices • Recognize the individual components of the big picture of computer networks

  3. Summary of Previous • Computer Network Layouts • Microcomputer-to-local area network • Microcomputer-to-Internet • Local area network-to-local area network • Personal area network-to-workstation • Local area network-to-metropolitan area network • Local area network-to-wide area network

  4. Summary of Previous • Sensor-to-local area network • Satellite and microwave • Cell phones • Computer terminal / microcomputer-to-mainframe

  5. Today’s Lecture • The Internet • History • Resource that can be shared • Applications of Internet • Client/Server Architecture • Internet Service Providers • HTML • Web Browsers

  6. Today’s Lecture • Searching the Web • Tips and Techniques • Search Process • Different Web search tools • Outlook Express • Summary

  7. The Internet • What is the Internet? • A global network of networks • It is based on Internet Protocol (IP) • A standard (Language) used over internet for computers to communicate with each other.

  8. Who can Join Internet? • Anyone with a computer and internet connection. • At home, office, public places etc. • Any network can join the Internet • Includes research, academic, community & commercial networks • Pakistan have seen tremendous growth of internet in past few years.

  9. Internet at different places

  10. Popularity of Internet Impact of Internet on Society

  11. The Internet • Connects over a hundred thousand networks from nearly 200 countries. • According to Internet World Statistics, internet users are 32.7% of total world population, with the annual growth of 528.1%. (2011 Report)

  12. Internet Growth Rate in Pakistan Up till 2010 16.78% of Pakistan Population was using Internet

  13. Where did internet come from? • Late 1960s, ARPA (Advanced Research Projects Agency). Supported by Department of Defense, USA. To share information within one university. • ARPANET. To connect USA universities and organizations to share info and communicate. TCP Protocol. • 1973 – ARPANET connects to Europe

  14. The ARPANET Team

  15. Brief History • Mid-1980s – NSFNet (National Science Foundation Network, USA) • Formed network between supercomputers • Internet of NSFNet was the link to ARPANET • No commercial traffic allowed • 1990s • ARPANET shut down • NSFNet abandoned • Commercial networks take over

  16. What’s so special about the Internet? • Developed for information and project sharing (academic purposes). • Original intention • to allow different machines to understand each other. • Excellent for broadcasting data and connecting computers: less reliable for security.

  17. What can be shared over internet? • Many subjects and formats available to share • Documents • Graphics, video & audio • Software (free & shareware) • Newspapers • Directories • Library catalogues & databases • Books & journals • Junk

  18. HEC Pakistan Online Digital Library

  19. Pakistani Internet Daily Newspaper

  20. Internet Applications • Electronic Mail (email) • A method of exchanging digital messages from an author to one or more recipients. • Some early email systems required that the author and the recipient both be online at the same time, in common with instant messaging. • Modern email operates across the Internet or other computer networks. • Domain mail server collects incoming mail and transmits outing mail

  21. Email

  22. Internet Applications • File Transfer Protocol (FTP) • It is a standard protocol used to exchange and manipulate files over internet • Its purpose is to remotely share files and software

  23. Internet Applications • Voice Over IP (VoIP) • VoIP (voice over IP) is an IP telephony term for a set of facilities used to manage the delivery of voice information over the Internet.

  24. Internet Applications • Telnet • A program that runs over your PC and connects it to a server on the network. • You can enter commands using Telnet program and they will be executed as if you were directly entering them on the server command prompt. • This allows you to control the server and communicate with other servers on the network.

  25. Telnet Example

  26. Internet Applications • World Wide Web • Web, is a way of accessing information over the medium of the Internet. • It is an information-sharing model that is built on top of the Internet. • It uses HTTP (Hyper Text Transfer Protocol) for communication • Web uses Web Browsers such as Internet Explorer. Firefox etc. to send data from one end to another end

  27. World Wide Web • Web page is a document that needs to be fetched • Browser gets documents from Web server • Web Server is the place where web pages are stored/hosted • Documents identified by Uniform Resource Locator (URL) e.g; http://www.ciit.edu.pk

  28. Enter URL in Address bar hyperlinks http Vertical Scroll bar COMSATS Web Page

  29. The World Wide Web - created to link documents held on different machines. • Developed at CERN by Tim Berners-Lee. • Employed existing ideas but employed in a new way on a vast scale. • Graphical browsers developed slightly later.

  30. Client/Server Architecture • WWW is based on a client/server architecture – processing at both ends Give me file X Here it is Desktop Client Remote Server Request made using http A computer elsewhere on the Internet holding information Your desktop computer

  31. Who is ISP? • Internet Service Provider (ISP) • Company that provides Internet access • Dialup • Connects to Internet through phone line • Modem connects to the phone line • Slow connection

  32. Access the Internet through ISP • High-speed access • Connect through a special line • 2 – 25 times faster than dialup • DSL, Cable, T1 are common

  33. Hyper Text Markup Language • HTML is used to make web pages. • IT describes how the web page may look like. • Simple Code syntax. <HTML> …….. …….. </HTML>

  34. Web Browsers • Used to read and translate HTML • Display web contents • Different browsers exists. • Microsoft Internet Explorer • Mozilla FireFox • Opera • Chrome • Safari

  35. Searching the Web

  36. Search Engines • Search engines are: • Web sites used to find information on the Internet • Searches are based on: • A word or a combination of words or topics • Examples of search engines are MSN, Google and AltaVista.

  37. Search Example To find some food recipes on the internet MSN home page appears as shown Open the MSN home page

  38. Search Example Type in some text and click the link Search button

  39. How to perform search • Use specific questions • A specific question is a question that you can phrase easily and one for which you will recognize the answer when you find it • Avoid explanatory questions • An explanatory question is an open-ended question that can be harder to phrase; it also is difficult to determine when you find a good answer

  40. Examples of Questions • Specific • What is the population of Pakistan. • Statistics will be shown as a result. • Explanatory • What causes depression? • Because there are multiple reasons which causes depression. • Not a single answer

  41. Web Search Process • Before beginning a Web search, decide whether the question is specific or exploratory.

  42. Search Process

  43. Using Search Engines Web search tools include four broad categories of sites: Search engines Directories Metasearch engines Other Web resources such as Web bibliographies

  44. Using Search Engines A Web search engine is a Web site (or part of a Web site) that finds other Web pages that match a word or phrase you enter The word or phrase you enter in a search engine is called a search expression A hit is a Web page that is indexed in the search engine’s database and that contains text that matches a specific search expression New Perspectives on the Internet, 8th Edition

  45. Google Search Engine New Perspectives on the Internet, 8th Edition

  46. Using Search Engines Using Web Directories It specializes in linking to other web sites and categorizing those links. It lists web sites by category and subcategory. Not a search engine by itself. New Perspectives on the Internet, 8th Edition

  47. Web Directory Example

  48. Using Search Engines Using Metasearch Engines: A metasearch engine is a tool that combines the power of multiple search engines New Perspectives on the Internet, 8th Edition

  49. Using Search Engines Using Web Bibliographies: The Web includes Web bibliographies, another category of resource for searching the Internet. Web bibliographies are also called resource lists, subject guides, clearinghouses,and virtual libraries New Perspectives on the Internet, 8th Edition

  50. Configuring Email Client on Computer

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