1. The Internet and the World Wide Web
Chapter 2A
The Internet and the World Wide Web

2. The Internet’s History
1969 – ARPANET
Developed by the Department of Defense
Connected universities and defense bases
1973 – ARPANET connects to Europe

3. ARPANET 1973

4. The Internet’s History
Mid-1980s – NSFNet
Network between supercomputers
Internet was the link to ARPANET
No commercial traffic allowed
1990s
ARPANET shut down
NSFNet abandoned
Commercial networks take over
Discussion point
Have students discuss the pros and cons of no central control for the Internet. Some discussion points can include copyright issues, free speech, advertisements and information access to all.

5. 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

6. U.S. Internet Growth

7. The Internet’s Major Services
The World Wide Web (WWW)
Developed in 1993 by Tim-Berners Lee
Allowed connection of documents
Required a browser to read documents
Electronic mail ( )
Instantaneous transmission of documents

8. The Internet’s Major Services
News
Often called newsgroups
Electronic discussions on several topics
File Transfer Protocol (FTP)
Sends and receives files
Teaching tip
Show a typical news group to the students in class. Be sure that you have connected and downloaded all posts before trying the demonstration.
Demonstrate the use of ftp to change a web site.

9. The Internet’s Major Services
Chat
Public real time conversation
Instant messaging
Private real time conversation
Peer-to-peer services
Allows sharing of files among users
Napster and Kazaa are examples
Illegal to share copyrighted material
Discussion point
Recently the pop artist Madonna posted several copies of her songs on Kazaa and other file sharing services. Instead of music, she talked at length about copyright infringement through music sharing. In retaliation, hackers hit her website and temporarily made her songs free to purchase. Who is right?

10. Accessing The Internet
Internet Service Provider (ISP)
Company that provides Internet access
Dialup
Connects to Internet through phone line
Modem connects to the phone line
Slow connection

11. Accessing The Internet
High-speed access
Connect through a special line
2 – 25 times faster than dialup
DSL, Cable, T1 are common

12. Understanding the Internet
The Internet allows accessing resources
The Web simplifies the Internet
The Web connects documents
Hypertext creates links between documents
Documents are stored on a web server
HTTP delivers documents
Teaching tip
Find out who has a web presence. If the site is appropriate, display it in class. Have the student discuss what is needed to establish and maintain a web presence.

13. Understanding the Internet
Web site is a collection of documents
Document is a web page
Pages are published to the web
Hypertext Markup Language
Creates web pages
Describes how pages should look
Content enclosed in tags
<tag>content</tag>
Teaching tip
Show your students how to access the HTML of an appropriate web site.

14. Understanding The Internet
Browsers
Read and translate the HTML
Display web content
Uniform Resource Locator (URL)
Address of a web page
Teaching Tip
Dissect the URL provided.

15. Understanding The Internet
Helper applications
Plug-ins
Enhance a browser’s functionality
Streaming audio and video
Sends the file in small chunks
Chunks downloaded while others play
Teaching point
Direct the students to several different streaming video sites. and are two excellent examples. Be sure your classroom browsers have the appropriate plug-ins.

16. Streaming Audio

17. Using a Browser And The WWW
Browser starts on the home page
Navigating the web
Enter a URL in the browser
Click a link
Links are typically blue underlined words
Image maps are picture links
When finished, close the browser

18. Searching the Web The Web is unorganized Directories Search engines
Categorize the Internet
Search engines
Find sites by keyword
Insider information
The search engine has become one of the hottest search engines on the planet. It is so popular, it’s name has become a verb. For example, “I googled the answer last night” is a phrase uttered on college campuses the world over.

19. Searching the Web Site searches Metasearch sites Sponsored links
Large sites have an internal search
Metasearch sites
Search several web sites at once
Sponsored links
Sites pay for better search results

20. Search Techniques Quote the exact phrase Use the keyword AND
Use the keyword NEAR
Avoid common words
Use the site’s advanced tools

21. MONITOR
A monitor or a display is an electronic visual display for computers.

22. History
Early electronic computers were fitted with a panel of light bulbs where the state of each particular bulb would indicate the on/off state of a particular register bit inside the computer. This allowed the engineers operating the computer to monitor the internal state of the machine, so this panel of lights came to be known as the 'monitor'. As early monitors were only capable of displaying a very limited amount of information, and were very transient, they were rarely considered for programme output. Instead, a line printer was the primary output device, while the monitor was limited to keeping track of the programme's operation.

23. Cont’d……….
Originally, computer monitors were used for data processing while television receivers were used for entertainment. From the 1980s onwards, computers (and their monitors) have been used for both data processing and entertainment, while televisions have implemented some computer functionality.
The first CRT monitor was created in 1987 by a German physicist named Karl Ferdinand. The first time it was used by regular consumers, though, was not as a computer screen, but rather as a 5' desktop calculator screen! Technology really has gotten smaller and smaller since those days!

24. Types of Monitor
The first type that comes with most desktop computers ;it look like a television screen and works in much the same way . This type of monitor uses a large vacuum tube ,called a cathode ray tube (CRT).
The second type ,known as flat –panel display ,was used primarily with portable computer in past .Today, flat penal monitors are popular features with desktop computers .

25. Categorized
All the Monitors can be categorized by the way they display colors………
Monochrome monitor display only one color (such as green ,amber, or white ) against a contrasting back-ground ,which is usually black. These monitors are used for text –only displays , where the user does not need to see color graphics.

26. Grayscale Monitors
Grayscale monitors display varying intensities of gray against a white or off-white background and are essentially a type of monochrome monitor .Grayscale flat – panel display are used in low –end portable system –especially handheld computers to cost down.

27. Colors Monitors
Colors monitors can display 16 colors and million colors . Today ,most new monitors display in colors. Many color monitors can be set to work in monochrome or grayscale mode.

28. Printing Devices

29. Printer Its types, working and usefulness

30. What is a printer?
An external hardware device responsible for taking computer data and generating a hard copy of that data. They print text and still images on the paper.

31. “Print Quality”
(1) Near typeset quality: A Lower quality print similar to the output of a type-writer. (2) Letter quality: Print made up by fully formed (solid line) characters. (3) Near letter quality: A print of high quality formed by multiple passes of print head over the same letter. (4) Standard quality: A high quality print formed by a single pass of the print head. (5) Draft quality: A print formed with minimum number of dots or lines and are smaller than the standard quality characters.

32. “Factors affecting print quality”
(1) DPI: It is a measurement of printer’s resolution indicating how many ink dots can be placed by the printer in one square inch. The higher the DPI, the sharper is image. (2) Type of printer: Each type of printer has its own capabilities of printing. Some types of printers produce high quality print while other produce low quality print. (3) Print Mode: The printing mode may also affect the quality. For example the draft mode increases the print rate but quality is reduced. (4) Toner: The quality and amount of toner also affects print quality.

33. “Dot Matrix Printer”
The term dot matrix refers to the process of placing dots to form an image.
Its speed is usually 30 to 550 characters per second (cps).
This is the cheapest and the most noisy printer and has a low print quality. Dot Matrix were 1st introduced by Centronics in 1970.

34. How Dot-Matrix works?
The dot matrix forms images one character at a time as the print head moves across the paper.
Uses tiny pins to hit an ink ribbon and the paper much as a typewriter does.
This printer arranges dots to form characters and all kinds of images.
9 to 24 vertical column pins are contained in a rectangular print head. When print head moves across the paper, pins are activated to form a dotted character image. These printers can produce carbon copies along with the originals.

35. Printers

36. “Advantages/Dis-advatages of Dot-Matrix”
(1) In-expensive.
(2) Low per page cost.
(3) Energy efficient.
Dis-advantages:
(1) Noisy
(2) Low resolution
(3) Limited fonts flexibility
(4) Poor quality graphics output.

37. “Printers for different users”
To choose a printer from a printer’s family following considerations are to be made.
(1) What’s the budget?
(2) Is color needed or just black& white?
(3) What is the Volume of the output?
(4) How important is the quality of the output?
(5) What special features are needed?
(6) Is the printer is to be used by a single user or a whole network?

38. “Printers for banks, large business organizations and companies”
In banks, large size business environments and companies printers with networking capabilities should be preferred which can increase productivity and reduce the cost without compromising on the quality. Of course laser printer is quite suitable choice but multi-functional printer and inkjet printer can also play vital role.

39. “Conclusion”
In fact computer world is incomplete without printers in the modern age of technology. A printer is one of the basic needs of every computer user and one can not utilize computer resources properly in the absence of a quality printer.