Internet/Web Basics

Margie Metzlermargie@netapp.com

Java 3.3.129

(408) 822-3185

http://www.geocities.com/webclassfremont/

http://www.geocities.com/margiemetz/

April 19, 2023

What is the Internet?A World Wide Computer Network

Definitions

Internet: the largest public Wide Area Network

Intranet: a private Wide Area Network, with access restricted to those within an organization

Extranet: a private Wide Area Network for a group of companies or organizations

World Wide Web: a huge collection (all) of the HTML documents that link to other documents

What is a Network? Networking is Communicating Three Types of Computer Networks

1. Peer to Peer

2. Local Area Network

3. Wide Area Network

1. Peer to Peer

Network Cable

PC PC

2. Local Area Network (LAN)

W/S

FileServer

W/S

The computing is done on the PC’s.

The file server holds and protects

your files.

3. Wide Area Network

PC

FileServer

PC

Santa Clara

PC

FileServer

PC

Sunnyvale

Leased phone lines

So what is the Internet?

The Largest Public Wide Area Network

TCP/IP

Basic Technologies TCP/IP : Transport Control

Protocol/Internetworking Protocol. Enables one computer to address and send data to another. IP handles addressing and TCP ensures delivery.

FTP: File Transfer Protocol. Service capable of moving files from one computer to another.

SMTP: Simple Mail Transport Protocol. The basis for Internet e-Mail.

What is on the Internet? World Wide Web Sites File Transfer Protocol Sites E-mail Telnet

What is the World Wide Web?

A huge collection of HTML documents

H Hyper

T Text

M Markup

L Language Documents that link to other

documents

HTML Current standard: 4.0 (but 3.2 is what

browsers do best) See www.w3.org to see what is

standard at any time Uses open and closed brackets Is a Markup Language rather than a

Programming Language Evolved from SGML

What is a Web Page? An HTML file (text-only) The HTML file may link to:

– Graphic Files– Sound Files– E-mail addresses– Other HTML files– Etc.

What is a Web Site? A group of HTML files A folder on a hard disk A collection of Web Pages

What is a Web Server? Computer holding the Web Site Software that lets the computer serve

the site to another computer

What do I need to Use the 'Net?

Computer (PC, MAC, etc) Connection (Modem or Ethernet Card

for LAN) Internet Service Provider Software to connect to ISP Browser

– Netscape Navigator, Microsoft Internet Explorer (various versions)

...and to create web pages?

Space on a Web Server Software to upload the web site to the

server Application to create HTML (Notepad,

vi)

Don’t I Need a Web Page Designer?

No…If you know HTML you can use Notepad or vi. You

can also use Microsoft Office but ….

But…– You may want to use software such as HomeSite by Allaire,

FrontPage by Microsoft, Dreamweaver by Macromedia, Netscape’s Composer, Adobe PageMill or Go Live, or Arachnophilia (http://www.arachnoid.com/arachnophilia/), or…

– WYSIWYG Editors don’t use “standard” HTML code.

– They inject extraneous code of their own, which is tedious to edit or remove.

History of the Internet Mainframe computers start to share data Person-to-Person communication

– E-Mail – Distribution Lists

Development of a Language Development of the first browser Hypertext and Graphics Introducing the World Wide Web!

History (continued)

1969, ARPANET launched: U. of Utah, SRI, UCLA, UCSB, by Advanced Research Projects Agency (ARPA) to ensure communications in case of a nuclear war

1976, AT&T launches UUCP (Unix to Unix Copy)

1969

ARPANET

1976

Packet switching

and UUCP

1983

TCP/IP

1990

ARPANET

dissolved

1984

DNS2001

We are

here!

1979

Usenet1986

NSF1992

WWW

History (continued) Usenet, 1979: UUCP link between Duke

and UNC

TCP/IP in 1983: >500 hosts

1984, Domain Name System (DNS) is introduced for automatic address resolution

1986: National Science Foundation creates NSFNET

1992: World Wide Web (>1,000,000 hosts)

World Wide Web

Developed at CERN, early 1990’s European laboratory for Particle

Physics Proposed by Tim Berners-Lee in 1989 Prototyped on NeXT (1990) Launched in 1992 Mosaic introduced in 1993

Who Sets the Standards?

The World Wide Web consortium www.w3.org Tim Berners-Lee

Components of a Web Site

Basic Web Pages (HTML)

Documents– Acrobat– HTML– Office

Components of a Web Site

Other– Forms– CGI scripts– Server-Side Scripting (CGI’s: PERL,

C++ etc.)– Client-side Scripting (JavaScripts)– Security (firewalls etc.)

Creating your site Get a domain name Get a server to serve your pages Create your HTML pages Upload them to your server

The Internet Challenge: Communicating Globally

Networks Operating systems Workstations Software People

Talking...

Major Issues

You can’t control what people see– They use different browsers: Netscape, Internet

Explorer, Lynx, Opera (and different versions)

– They can turn off graphics and change text colors and sizes on their browsers

– Mac, UNIX, PC operating systems give users much different views

– Servers don’t always support your HTML code. (60% are UNIX running Apache)

– They don’t like being required to download plug-ins

– They use different monitors/screen sizes/resolutions

Who’s Using What? Servers: 60% UNIX running Apache, probably greater in

Silicon Valley. The rest are other and Microsoft NT servers.

Browsers: (http://www.statmarket.com/SM?c=stat022201):

“As of Feb. 21, 2001, Microsoft Internet Explorer's usage share was 87.71 percent worldwide, up from only 86.08 percent on June 18, 2000, according to WebSideStory's StatMarket, the recognized authority on global Internet user trends. Netscape's global usage share, meanwhile, was 12.01 percent on Feb. 21, down from 13.90 percent in June. Usage share is the percentage of people worldwide that are using a particular browser on the Web.”

Microsoft

Netscape

Other

Who’s Using What?(http://browserwatch.internet.com/stats.html):

Browser Types Visiting BrowserWatch

(Must Have .25% Share Or Better)Browser Value Percent

Microsoft Internet Explorer 4291 68.8%

Netscape Navigator 1083 17.3%

Opera 218 3.49%

4.72 (X11) 94 1.50%

AvantGo 3.2 84 1.34%

IBrowse 50 0.80%

Powermarks-3.5) 48 0.77%

JennyBot 47 0.75%

MSProxy 27 0.43%

FavOrg 23 0.36%

Lynx 23 0.36%

Graphics: Types

GIF: Graphical Interchange Format (CompuServe)

JPEG: Joint Photographer’s Experts Group

PNG: (W3C)

More on Graphics Monitors: resolutions of 640x480 to

1600x1200 Pixels: basic building blocks A pixel has complete set of red, blue

and green dots Size of pixel depends on the video

card, how the hardware is configured, and size of the screen

More Graphics

Color models:– Pantone (Print media)– RGB (Red, Blue, Green.) Monitors– CYMK (Cyan, Magenta, Yellow and

Black.) Printers 216 Web-safe colors

Still More Graphics Resolution Bandwidth File size: shouldn’t be over 50-60 KB.

(Users don’t like downloading big graphics unless they’re really necessary.)

Usability Issues How well can users use your site? Some of the rules we’ve used for print

no longer apply.

Usability Definitions

Usability describes whether people can achieve their goals in a simple and pain-free manner.

Six Attributes of Usability

Learnability - System enables achieving tasks on first time use

Success - System enables the user to complete work without errors

Throughput - System enables rapid completion of work

Satisfaction - System is pleasant to use System Integrity - System does not enable

the user to injure it Health and Safety - System does not enable

the user to injure herself

Usability Issues

Audience– Line speed?– Firewall issues?

Special Technology Requirements– Plug-Ins?– Bells & whistles?

Develop for the lowest common denominator

Writing for the Web

Web Facts 79% of users always scan; only 16%

read word-by-word

Reading from computer screens is 25% slower than from paper

Web content should be 50% the size of its paper equivalent

Paper vs. Online Publishing

Paper

Document forms a whole, and the user is focused on the entire set of information

Paper vs. Online Publishing

Web Site Publishing Split documents into multiple hyperlinked pages Make sure each page stands on its own Lower word count; readers read about 25% slower Get to the point: Web users are task-oriented and

impatient Don’t exaggerate: Credibility is critical Use an informal and immediate writing style Use simple sentence structures Update pages often Use up-to-date statistics, numbers and examples

Screen Size. 100 words on a Palm-sized computer is a lot to read. The same text at 1024 x 768 is a reasonable amount.

Resolution. Print text is 600 dpi. Online text is 72 dpi. This difference produces a jagged text that is more difficult to read and tires eyes.

"Noise." Everything on screen that distracts from the message of the content: banner ads, animations, meaningless graphics, and formatting are all "noise".

Issues that Affect Writing Style

Choose appropriate fonts and colors.

Use online fonts and Web-safe colors.

Use Meaningful sub-headings.

Use Bulleted lists.

Use only one idea per paragraph.

Chunk information together.

Use half the word count of conventional writing.

Writing Suggestions

Simplicity

Credibility

Outbound links

Humor: But use with caution (remember “World-Wide”)

Speed: Users want to get their information quickly

What Users Want

(Spool, Jared et al, Web Site Usability, p. 75.) The more white-space there was on a site, the less successful

users were at finding information

The more white-space, the lower users rated the site in terms of:– Finding things easily– Ease of reading– Ease of searching– Overall appearance– Ease of use– Productivity

Why? Skimming is different from reading. People are “hunting” for information on the Web. White-space spreads out information and slows the “hunt.”

White Space

Conventional wisdom: people don’t like to scroll, hence information should not be “below the fold,” in newspaper parlance, or below the screen such that you have to scroll to read.

Not true:

– Different sized screens, resolutions etc. make it impossible to know how big anyone’s screen is.

– Usability studies show no one minds scrolling down. (They do get annoyed at strolling across, however…).

– But… users quit reading when they hit a horizontal line or a line of very small text.

Scrolling

Studies indicted that graphic design has no impact on a site’s usability.

But…. users reported that they couldn’t concentrate when there was animation on the screen.

Graphics

You lose 75% of your readers on each click they have to make to find information.

However, readers will continue to click if they think the link will take them to the information they want.

Links

Skills needed HTML, JavaScript, Java, PERL

programming Writing for the Web Design Management of Internet, Extranet,

Intranet Graphic artists

That’s All, Folks!