Lecture 1 How The Web Works

Internet Fundamentals 

Contact Information: 

John Anthony Rose, PhD (Associate Professor)     

APU Institute of Information Communication Technology Office Address: B-414 Phone: x4414 E-mail: [email protected] Web-page: under construction.

Texts and References 

Our Primary Texts 

‘Internet & World Wide Web: How To Program’, 3rd Ed. Authors: H. M. Deitel, P. J. Deitel, and A. B. Goldberg  Publisher: Pearson Education (2004)  ISBN (Int’l Standard Book Number): 0-13-145091-3 

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‘HTML for the World Wide Web’, 5th Ed. (Elizabeth Castro) Publisher: Peachpit Press (2003 ）  ISBN: 0-321-13007-3 

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Other Text Resources: 

‘Learning Web Design: A beginners guide to HTML, Graphics, and Beyond ’, 2nd Ed, (Jennifer Niederst) Publisher: O’Reilly (2003)  ISBN: 0-596-00484-2 

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‘HTML for Dummies’ (E. Tittel and S. E. James) 

Wiley (1997), ISBN: 0-7645-0214-X

Course Syllabus (2007 Spring Q2) 

A. Introduction to the Internet and the Web Lecture 1: Introduction to the Internet  Lecture 2: The Netscape Internet Browser 

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B. XHTML     

Lecture 3: Lecture 4: Lecture 5: Lecture 6: Lecture 7: 

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Introduction to XHTML Design Fundamentals; XHTML Lists HTML Formatting; Simple Tables Web Page Division and Organization; Complex Tables Image Maps and Frames

Midterm Exam (In Class) and Final Project Assignment (1st Half).

C. Cascading Style Sheets (CSS)      

Lecture 8: Introduction to CSS: Creating Styles Lecture 9: Applying Styles: Internal and External Style Sheets Lecture 10: Formatting with Styles I: Font Properties Lecture 11: Formatting with Styles II: Text Properties Lecture 12: Layout with Styles I: Flow and Positioning Lecture 13: Layout with Styles II: The Box Model -----------------------------------------------------------------------------------------------------------------------------------------------------------------------

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Final Exam and Final Project Due (Both 1st and 2nd Halves).

Course Evaluation (Grading) 

The final grade (100%) will be awarded using the following criteria for evaluation: 

Attendance: 20% 

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Mid-Term Exam (In Class): 　 30% 

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Please come to every class. After Lecture 7

Final Project (Personal Web-page): 15% 

Due during Exam Week

Final Exam (In Class): 35%  Note: The above schedule and weights are tentative. 

Course Methodology 

Lecture materials will be distributed at the beginning of each class, Followed by the Lecture…  Where possible, examples will be presented with figures. 

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Each class is 95 minutes. After each lecture-period: 

students will be provided time for practice (as time permits). 

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For a total of 95 minutes (lecture + practice)

Teaching Assistants (TAs) will be available to answer questions during the practice period.

Note: substantial practice and work beyond the class period WILL be required.

Miscellaneous Instructions 

Students should bring their own data storage devices: 

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Necessary for storing work: 

USB 2.0 Flash Memory  64 MB or higher  Windows XP Compatible

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CD-RW  650 or 700 MB

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Floppy Disk  3.5’, 1.4 MB

These can be purchased at the APU Book Store.

Lecture 1 – Introduction to the Internet

Some Web Resources for Ch.1 

www.wikipedia.org 

The freely available on-line Encyclopedia, ‘Wikipedia’ Provides comprehensive discussions of Internet and WWW topics;  Available in 10 languages! 

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www.deitel.com  

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The web-site of one of our primary texts. This site provides various resources…

netforbeginners.about.com 

The About.com Internet for Beginners Guide 

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History and workings of the Internet and World Wide Web.

www.learnthenet.com/english/index.html 

The Learn the Net Website 

Contains a complete overview of the Internet and the WWW.

The Internet (‘The Net’) 

This course will be focused on the World Wide Web (WWW)… Specifically, in the creation of web documents (XHTML, CSS).  But first, let’s talk about the Internet… 

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Which provides the underlying basis for the Web.

The Internet is a publicly accessible, world-wide network of computer networks 

This is a Cooperative Effort: 

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No single company owns the Internet;

The Net Achieves a Virtual Network: The illusion of a single network.  Achieved by governing information transfer by rules and standards. 

A Brief History of the Net 

The Net has a D.O.D. origin 

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DARPA: The Defense Advanced Research Projects Agency

ARPANET: The ‘Grandfather’ of the Internet The first node (computer) was operational on Oct 29, 1969  Big unexpected benefit: Electronic Mail (e-mail). 

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One Primary Goal of ARPANET: 

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Use quickly became peaceful…

Allow many users to send/receive information along the same phone lines…

Rules (‘protocol’) for communicating on ARPANET: 

Became known as Transmission Control Protocol (TCP) Information exchanged in small units = packets  Exchange by ‘packet-switching’… 

Packets from many users all mixed together;  Replaces dedicated lines between senders and receivers.  Drastically lowers costs. 

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TCP ensures correct, intact delivery of each packet.

The Internet Protocol 

As the Net evolved… 

Organizations world-wide began implementing their own networks; Both intranets (within each organization)  And internets (between organizations). 

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Big Challenge: 

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develop a set of rules allowing them ALL to communicate!

To achieve smooth packet travel, these rules must:  

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Using a wide variety of hardware/software

Provide a unique address for each computer on the Net. Be communicable to all computers on the Net.

This set of rules is called the Internet Protocol (IP). 

The combined set of protocols: TCP/IP 

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ＴＣＰ operates ‘on top of’ ＩＰ .

The first TCP/IP Network: 

National Science Foundation: USFNet (Jan. 1, 1983)

Internet Increasing Exponentially 

At first, the Internet was used mostly by National Labs/Universities… However, the military began large-scale use;  Also, the Government eventually allowed commercial use. 

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Growth since then has been monitored. See figure…  Growth is Exponential… (Note the log scale) 

Dec, 2003: > 108 clients.  Jan, 2006: > 109 clients! 

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Old worry: Net will become saturated! …and performance will decline.  However, the reverse is actually true: 

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Businesses need to optimize intranet performance. Thus…

Information carrying capacity (bandwidth) has increased tremendously.

The World Wide Web (WWW) 

The World Wide Web (WWW) was created in 1990 By Tim Berners-Lee of CERN (Switzerland)  This system allows users to view multimedia-based documents: 

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Use of the Web exploded in 1993… 

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With creation of the ‘Mosaic’ web-browser by the NCSA  The National Center for Supercomputing Applications  Mosaic featured a user-friendly Graphical User Interface (GUI)

The WWW is a publicly-accessible, world-wide network of documents 

Thus, the Web is not the same as the Internet. 

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Text, Graphics, etc.

Rather, the Web is a service, that operates ON the Internet.

In this course, our focus is on the Web… 

Specifically, we will focus on creation of Web documents: 

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Mainly via XHTML and CSS (possibly a little JavaScript).

But first, let’s briefly discuss how the Web works.

Some Basic WWW Terms 

The Web is the combination of 4 simple ideas: 

Hypertext: 

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the ability to move within or between documents, through internal connections (hyperlinks);

Resource Identifiers: the ability to locate a particular resource (computer, printer, etc) on a network…  Via Universal Resource Locators (URLs) 

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The Client-Server model of Computing: 

Client software/computers make requests for resources (data) 

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more on this next lecture.

A program called a Web Browser.

Server software/computers provide the requested resources.

Markup Language: Characters included within the text indicate how the text should be formatted…  HTML = Hypertext Markup Language 

How the Web Works 

These 4 ideas work together on the Web, as follows: 1. A Client program (browser) requests information from a Server; e.g., a Web-page or a file.  Service provided by an Internet Service Provider (ISP) 

2. The Server is identified using its Network Address; From the Server part of the information’s URL.  Accomplished by a special server:  A Domain Name System (DNS) server. 

3. The requested information is quickly returned to the client. 4. The Browser displays the returned information… 

Typically on a computer screen.

5. The Markup Language controls how the retrieved text is displayed. 

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Hyperlinks in the Web Page then allow page-to-page travel… 

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As a Web Page, integrating all text, images, links, etc, as directed.

Often called web ‘surfing’.

Web pages are often grouped into structured units, or Websites.

World Wide Web Consortium (W3C) 

In 1994, Tim Berners-Lee founded the W3C 

Mission: to develop non-proprietary technology for the Web. 

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Non-proprietary = Freely accessible to everyone.

Primary Goal: Establish Universal Web accessibility,  Regardless of language, culture, or ability. 

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Thus, W3C is the Web’s ‘United Nations’.

Another Goal: Web Standardization: 

Establish standard technologies for uniform Web use: 

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‘Recommendations’.

Some examples: HTML – Hypertext Markup Language (‘legacy’ tech.: out-dated)  XML – Extensible Markup Language  XHTML – Extensible Hypertext Markup Language  CSS – Cascading Style Sheets 

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We will discuss all of these, in the coming lectures.

Visit W3C Web-page, at: http://www.w3.org

Conclusion 

In this Lecture, we have introduced: 

The Internet: 

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The World Wide Web: 

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A world-wide network of computers A world-wide network of documents…  and the relationship between these two terms.

Along with brief discussions of: Internet protocols for communication (TCP/IP);  Basic Web Functionality. 

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In the next Lecture, we continue our discussion… 

With a detailed tour of a popular Internet Browser: Netscape. 

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A tool for Web Browsing.

We will then discuss various other Web services: Electronic mail (e-mail)  Instant Messaging 

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…And become familiar with the differences between the various browsers.

Task for Today 

Open the Internet Browser, Netscape 7.2:  Then,

visit each of our suggested web resources:

The Web Encyclopedia, Wikipedia  Our textbook’s web-site (Deitel.com).  The About.com Internet for Beginners Guide  The Learn the Net Website 

 Also

visit the Web page of the WWW consortium.