B.S Ist semester

1. Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill Technology Education
McGraw-Hill Technology Education Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.

2. Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill Technology Education
Chapter 2A
The Internet and the
World Wide Web

3. 2A-3
The Internet’s History
• 1965- ARPA project
– ARPA of the US department of defense
started a project in 1965
– Purpose was to connected universities and
defense bases with each other

4. The Internet’s History
• 1969 ARPANET
– The network established in 1969 and was
named ARPANET
– Initially was consisting of only four (04) host
computers
• ARPANET 1973
– Extended to the whole Europe
2A-4

5. 2A-5
ARPANET 1973

6. 2A-6
The Internet’s History
• 1980-National Science Foundation (NSF)
– Joined the project in 1980 when Department of
Defense stopped funding
• Mid-1980s – NSFNet
– Network between 5 supercomputers centers for
academic and research purpose
– Initially they used ARPANET for connection but the
existing ARPANET was unable to handle that
much load and thus they started their own network
NSFNet
– No commercial traffic allowed by NSFNet

7. The Internet’s History
• Internet
– The link between ARPANET, NSFNet and
other networks was called Internet
– Definition:
• The global network of networks is called
Internet
• Internetworking
– The process of connecting different
networks
2A-7

8. The Internet’s History
2A-8

9. The Internet’s History
• 1990s
–ARPANET shut down in 1990
–NSFNet funding was disconnected in
1995
–Commercial networks take over
2A-9

10. 2A-10
Today and the Future
• 100,000 new web sites per month
• More than 50% of U.S. households
online
• Access is available throughout the U.S.
• Eventually access will be global

11. 2A-11
U.S. Internet Growth

12. The Internet’s Major Services
• The World Wide Web (WWW)
• Next chapter
– Electronic mail (e-mail)
– News
– File Transfer Protocol (FTP)
– Chat
– Instant messaging
– Online services
– Peer-to-peer services
2A-12

13. 2A-13
Understanding the World Wide Web
• World Wide Web
– Also called Web or WWW
• Started in1989-
– At European Particle Physics Laboratory in
Geneva, Switzerland
• Purpose
– To create a simple way to access any
document that are stored on a network

14. Understanding the World Wide Web
• 1993 -Tim-Berners Lee
– In 1993 Tim-Berners Lee gave the idea to
linked documents stored on different
computers across the world (on different
networks) or on different computers on a
network
2A-14

15. Understanding the World Wide Web
2A-15

16. How the web works
• The working of web need:
– Hypertext document
• Collection of text files, pictures, sounds, movies
– HTML language
• A markup language used to create hypertext documents
(called Web Page)
• These documents are linked through hypertext links (also
called hyperlinks)
• Web site are formed
– A collection of interrelated web pages is called Web Site
– Hypertext transfer protocol (HTTP)
• To support web pages
2A-16

17. How the web works
• Publishing a web page
– Uploading a wed page on server is called
publishing a page
– Also called posting a page
2A-17

18. Web Browsers
• A software application design to find a
hypertext document (Web page) and
then open the Web page on the user
computer
• Examples:
– Internet Explorer
– Mozilla Firefox
– Google Chrome
– etc.
2A-18

19. Uniform Resource Locator (URL)
• An Internet address of a web page is
called URL
– Format:
• Type:addresspath
– Type: specify type of the server: web server or file
server
– Address: address of the server
– Path: location within the file structure of the server
2A-19

20. 2A-20

21. • Wed document in URL
2A-21
WedWed
DocumentDocument

22. 2A-22
Understanding The Internet
• Helper applications and multimedia
contents
– Limitation of web-browsers:
• Browsers individually cannot display every type
of contents (video, audio, animations)
– Solutions to the problem
• Plug-ins are the special application softwares
that are used to play the contents in real.
• Enhance a browser’s functionality
• Used for Streaming audio and video
• Sends the file in small chunks
• Chunks downloaded while others play

23. 2A-23
Streaming Audio

24. 2A-24
Using a Browser And The WWW
• Start the browser
• Enter the URL
– Three methods are used for entering URL
• The home page of the web site will load in browser
window
• Use hyperlinks to navigate through the website
• When finished, close the browser

25. 2A-25
Searching the Web
• The Web is unorganized collection of
billions of documents from different
sources
• It is too difficult to get honest, trusty and
accurate information from the web easily
• To solve this problem:
– Search engines: are used

26. Searching the Web
• Types of search engines:
– Directories-based
• Categorize the documents into subjects i.e.
educationschoolsubjectcomputer
• Example:
– www.looksmart.com/
– Keyword based
• Find sites by keyword
– www.google.com
2A-26

27. Searching the Web
• Problems in search engines
– Sponsored links
• The links (web sites) for which the owner pays to the
search engines owners for displaying their links at the top
of the links in the search engines windows
– Irrelevant documents are retrieved
• Solutions to the problems
– Website-specific searching tool
• www.microsoft.com, www.cnn.com
– Advanced search: uses form having filters
• www.google.com, www.yahoo.com
2A-27

28. 2A-28
Searching the Web
• Metasearch sites
– A metasearch engine is a search tool that
sends user requests to several other
search engines and/or databases and
aggregates the results into a single list or
displays them according to their source.

29. • www.mamma.com
2A-29

30. 2A-30
Search Techniques
• Quote the exact phrase
• Boolean operators in search
• Use the keyword NEAR
• Avoid common words
– Is, or, no etc.
• Use the site’s advanced tools
– www.google.com
– www.yahoo.com
• See next slide

31. 2A-31

32. Search Techniques
• Logical operators: AND, OR, NOT
2A-32

33. 2A-33

34. Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill Technology Education
Chapter 2A
End of Chapter