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Lecture #3: The Internet

and the World Wide Web

After today’s class, you will be able to:

Discuss the history of the Internet Explain how to access and connect to the Internet Analyze an IP address Identify the components of a Web address Explain the purpose of a Web browser Search for information on the Web Describe the types of Web sites Recognize how Web pages use graphics, animation, audio, video, virtual reality, and plug-ins Describe the types of e-commerce Explain how e-mail, FTP, newsgroups and message boards, mailing lists, chat rooms, and instant messaging work Identify the rules of netiquette Identify the steps and tools required for Web publishing

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Networks

Used to:Get InformationConduct BusinessAdvertiseShopTalk to OthersAccess Other ComputersSend Messages

History

Advanced Research Projects Agency created ARPANET in the late 1960s.1970s more universities were being connected and standards were being established for data transmission.1986 NSF connected its 5 supercomputers to the Arpanet, forming the Internet.1989 the World Wide Web was introduced to aid communications for scientists working at CERN.1990s millions of people are beginning to connect to the Internet.1995 NSFnet returned to a research network.

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The Internet

The Internet is a vast system of millions of computers worldwide, connected by communication lines throughout the world. It is also known as the Net. More than 64 million adults regularly use the Internet today in the US alone.

Linking Networks to the Internet

Modem

Internet Provider

Mainframe

Router

Network Network

NetworkNetwork

Regional NetworkRegional Network

Router

Satellite Link

Router

Network Access

PointNetwork Access Point

Computer Workstation

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What is the World Wide Web (WWW) ?

A worldwide collection of electronic documentsAlso called the WebEach document is called a Web pageCan contain text, graphics, sound, video, and links to other Web pagesA Web site is a collection of related Web pages

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Types of Web pages

Portal – offers a variety of services such as news, search engines, maps, email, weather …

NewsInformationalBusiness/Marketing AdvocacyPersonalEducationEntertainment

Web BrowsersA web browser is a program that is used to look up information and URL addresses on the Internet. These are programs such as Netscape and Microsoft Internet Explorer.

Microsoft Internet Explorer

Netscape

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URLsA URL or Universal Resource Locator is an address for finding information on the web. It is similar to a telephone number or mailing address.Example: http://www.nasa.gov

http:// Hypertext Transfer Protocol Protocol interpretationwww On the World Wide Web Format information

nasa National Aeronautics Name of organizationand Space Administration

gov Government site Domain of organization

Other sites may have edu, com, or org at the end of the URL. edu educational sitecom commercial siteorg nonprofit organization

Search EnginesA search engine is a program that allows you to search specific topics. Search engines and guides are used to find information when a URL address is not known.

Yahoo, Excite, and WebCrawler are some

common search engines used on the Internet.

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HTML

HTML or hypertext markup language is the means by which documents are created. These documents can have text, sounds, graphics, animation, and links to a vast database of information.

NBC’s web page

NBC’s web page HTML code

E-MailE-mail or electronic mail is used to send messages to anyone, anywhere in the world.

Screen of an e-mail message

An address, much like a URL, finds a person’s “mail box”location.

Common uses:

• To say hello• Business

transactions• Business

communications• Interoffice messaging

• Sending resumes

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Terminology

Upload- your computer to serverDownload – server to your computer

File Transfer Protocol – standard for publishing and viewing web pages.

Intranet - name used to refer to a network within a single organizationInternet - name used for network connecting other unrelated networksWorld Wide Web - the part of the internet with websites

Server – computer that manages the network resourcesClient – access contents of the server

Homework

Reading Assignment:Discovering Computer 2005 pages 180 - 193

In class Exercise:Do the Scavenger Hunt on the Internet