lecture 1 internet website

8/17/2019 Lecture 1 Internet WebSite

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Chapter 1:

Introduction to the Internetand Web

By: Dr. Patrick D. Cerna

MS Agricultural Information and Communication Management, Haramaya University


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Objectives

At the end of the chapter, the students will be able to

know:

• the foundation of Internet

• the technologies in the internet

• Website format and style

• Type of website

• Tools in developing a website


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Internet

• No one owns it

• It has no formal management organization.

• As it was originally developed by the Department

of defense, this lack of centralization made it lessvulnerable to wartime or terrorist attacks.

• To access the Internet, an existing network need to pay a small registration fee and agree to certain

standards based on the TCP/IP (TransmissionControl Protocol/Internet Protocol) .


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The uses of the Internet

• Send e-mail messages.

• Send (upload) or receive (down load) files

between computers.

• Participate in discussion groups, such as

mailing lists and newsgroups.

• Surfing the web.


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What is Web?

• The Web (World Wide Web) consists of informationorganized into Web pages containing text and graphic

images.

• It contains hypertext links, or highlighted keywords

and images that lead to related information.

• A collection of linked Web pages that has a common

theme or focus is called a Web site.

• The main page that all of the pages on a particularWeb site are organized around and link back to is

called the site’s home page.


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How to access the Internet?

• Many schools and businesses have directaccess to the Internet using special high-speed communication lines and equipment.

• Students and employees can access throughthe organization’s local area networks(LAN) or through their own personalcomputers.

• Another way to access the Internet isthrough Internet Service Provider (ISP).


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How to access the Internet?• To access the Internet, an existing network need to

pay a small registration fee and agree to certainstandards based on the TCP/IP (TransmissionControl Protocol/Internet Protocol) referencemodel.

• Each organization pays for its own networks andits own telephone bills, but those costs usuallyexist independent of the internet.

• The regional Internet companies route and forward

all traffic, and the cost is still only that of a localtelephone call.


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Internet Service Provider (ISP)

• A commercial organization with permanent

connection to the Internet that sells

temporary connections to subscribers.• Examples: Prodigy, America Online,

Microsoft network, AT&T Networks.

• In Ethiopia: Ethiopian telecommunication(ETC)


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How to access the Web?

• Once you have your Internet connection, thenyou need special software called a browser to

access the Web.

• Web browsers are used to connect you toremote computers, open and transfer files,

display text and images.

• Web browsers are specialized programs.• Examples of Web browser: Netscape

Navigator (Navigator) and Internet Explorer.


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Client/Server Structure of the Web

• Web is a collection of files that reside on computers,

called Web servers, that are located all over the world

and are connected to each other through the Internet.

• When you use your Internet connection to become

part of the Web, your computer becomes a Web client

in a worldwide client/server network.

• A Web browser is the software that you run on yourcomputer to make it work as a web client.


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Hypertext Markup Language

(HTML)• The public files on the web servers are ordinary

text files, much like the files used by word-

processing software.• To allow Web browser software to read them,

the text must be formatted according to agenerally accepted standard.

• The standard used on the web is Hypertextmarkup language (HTML).


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Hypertext Markup Language (HTML)

• HTML uses codes, or tags, to tell the Web browsersoftware how to display the text contained in thedocument.

• For example, a Web browser reading the following line of

text: A Review of the BookWind Instruments of

the 18th Century

• recognizes the and tags as instructions to

display the entire line of text in bold and the and tags as instructions to display the text enclosed by thosetags in italics.


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Addresses on the Web:IP Addressing

• Each computer on the internet does have aunique identification number, called an IP

(Internet Protocol) address.

• The IP addressing system currently in use on

the Internet uses a four-part number.

• Each part of the address is a number ranging

from 0 to 255, and each part is separated from

the previous part by period,

• For example, 106.29.242.17


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IP Addressing

• The combination of the four IP address parts provides 4.2 billion possible addresses (256 x256 x 256 x 256).

• This number seemed adequate until 1998.

• Members of various Internet task forces areworking to develop an alternate addressingsystem that will accommodate the projected

growth.• However, all of their working solutions require

extensive hardware and software changesthroughout the Internet.


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Domain Name Addressing

• Most web browsers do not use the IP address t locateWeb sites and individual pages.

• They use domain name addressing.

• A domain name is a unique name associated with aspecific IP address by a program that runs on anInternet host computer.

• This program, which coordinates the IP addresses anddomain names for all computers attached to it, is calledDNS (Domain Name System ) software.

• The host computer that runs this software is called adomain name server.


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Domain Name Addressing• Domain names can include any number of parts separated by

periods, however most domain names currently in use have onlythree or four parts.

• Domain names follow hierarchical model that you can follow

from top to bottom if you read the name from the right to the

left.• For example, the domain name gsb.uchicago.edu is the computer

connected to the Internet at the Graduate School of Business

(gsb), which is an academic unit of the University of Chicago

(uchicago), which is an educational institution (edu).

• No other computer on the Internet has the same domain name.


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Uniform Resource Locators

• The IP address and the domain name each identify a particularcomputer on the Internet.

• However, they do not indicate where a Web page’s HTMLdocument resides on that computer.

• To identify a Web pages exact location, Web browsers rely on

Uniform Resource Locator (URL).• URL is a four-part addressing scheme that tells the Web

browser:

What transfer protocol to use for transporting the file

The domain name of the computer on which the file resides The pathname of the folder or directory on the computer on

which the file resides

The name of the file


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Structure of a Uniform Resource Locators

http://www.chicagosymphony.org/civicconcerts/index.htm

protocol

Domain name

pathname

filename

http => Hypertext Transfer Protocol


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HTTP

• The transfer protocol is the set of rules that the

computers use to move files from one computer to

another on the Internet.• The most common transfer protocol used on the

Internet is the Hypertext Transfer Protocol

(HTTP).

• Two other protocols that you can use on the

Internet are the File Transfer Protocol (FTP) and

the Telnet Protocol


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How to find information on the Web?

• A number of search tools have been developed andavailable to you on certain Web sites that provide

search services to help you find information.

• Examples:

Yahoo www.yahoo.com

Excite www.excite.com

Lycos www.lycos.com

AltaVista www/alta-vista.com

MSN WebSearch www.search.msn.com


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How to find information on the Web?

• You can find information by two basic means.

• Search by Topic and Search by keywords.

• Some search services offer both methods, others onlyone.

• Yahoo offers both.Search by Topic

You can navigate through topic lists

Search by keywords

You can navigate by entering a keyword or phase intoa search text box.


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Impact of the Internet and the Web

• The Internet and the Web have impacted

– Communication

– Education

– Entertainment

– Business


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TYPES OF WEBSITE

• Static Website - Static websites can only really be updated

by someone with a knowledge of website development.

Static websites are the cheapest to develop and host, and

many smaller companies still use these to get a web presence.

• Dynamic Website - Dynamic sites on the other hand can be

more expensive to develop initially, but the advantages are

numerous. At a basic level, a dynamic website can give thewebsite owner the ability to simply update and add new

content to the site


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Web Pages exist as individual files

Some file types that may be familiar

MS WORD DOC .doc, .docx

MS EXCEL .xls, xlsx

ADOBE FILES: .pdf, .psd, .ai.

Digital Camera Files .jpg, .tiff

Examples of typical static web page

files

.htm

.html

Static Websites - Pages


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Pages typically contain text,

hyper links, photos, and graphics

Pages may also contain animated

or interactive media such as:

Movie Clips (YouTube etc.)

Adobe Flash Presentations

Microsoft Silverlight

Other media types

Pages are called Static

because text, photos, and other

content will not change unless the

actual web page file itself is edited.

A web page editing program and

Static Websites - Pages (continued)


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Pages are associated with each

other by a menu of links or

“Navigation Menu”

Changes to the main Navigation

Menu will require an edit to every

web page that contains this menu.

Web development software can

automate Navigation Menu

maintenance, but pages will still

need to be re-published for changes

to take effect.

footer

Static Website Navigation


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Pages are published by uploading

files to a Web Hosting Computer

Directly from within the development

software

By transferring individual or groups

of files with a File Transfer program.

Maintaining a networked folder with

the Web Hosting Server

Static Web Page Files are

published by physical transfer fromthe development PC to a Web Hosting

Computer

Static Websites - Publishing


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STATIC WEBSITE

Advantages of static websites

• Quick to develop

• Cheap to develop

• Cheap to host

Disadvantages of static websites

• Requires web development expertise to update site

• Site not as useful for the user • Content can get stagnant


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Dynamic Websites

Dynamic Websites


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Employ Dynamic pages that exist as files

with extensions based on the type ofprogramming used.

.jsp , .cfm, .pl, .php, .asp, .aspx

Pages are Dynamic in that they can draw

ever changing Content from external

information sources

Pages can provide Create, Retrieve,

Update, and Delete functions for company

records

Pages may not require

republishing

Dynamic Websites

D i W b i F


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Your basic “CRUD”

Pages are capable of providing

interactivity such as:

Forms to request information or

submit sales leads

Internal searches within your site

Registration and Login, personal

profile maintenance, and

authenticated/secure access toprotected or premium content

Dynamic Websites - Features

D i W b it F t ( ti d)


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Dynamic Product Catalogs and

online sales (Ecommerce)

Information that is already

maintained within company I.T.

Systems such as Databases,

Spreadsheets, and text files can be

leveraged as Web Content.

Access can be granted to allow

customers to maintain their own

information.

Dynamic Websites - Features (continued)


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DYNAMIC WEBSITE

Advantages of dynamic websites

• Much more functional website

• Much easier to update

• New content brings people back to the site and helps in the

search engines

• Can work as a system to allow staff or users to collaborate

Disadvantages of dynamic websites• Slower / more expensive to develop

• Hosting costs a little more

I D i Ri ht f Y O i ti


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Dynamic websites are a better choice when you:

need custom programming to accommodate your unique business needs

need pages that must pull information from sources external to the website proper

need to be able to easily add and edit web pages (Content) from within a browser

need web pages that will display and update records from your information systems

need to give one or more staff members access to edit the site

need convenient access to setup common interactive features such as Article

Publishing, Event Calendaring, Blogs, Secure Login, Ecommerce, and others.

Is Dynamic Right for Your Organization


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Kinds of Web Sites: NOTES

• Part of this class requires you to create aWeb site of your own

• First you must decide what type of Web siteyou want to create

• The different types of Web sites are:

– Personal

– Organizational/Topical

– Commercial


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Web Page Tools

• HTML Hypertext Markup Language

– A formatting language used to create Web Pages

– Regardless of the tool used: HTML is the final result• Scripts, Applets, Servlets, and ActiveX Controls

– Short programs run by the Web browser – embedded

into HTML

– Makes a Web page dynamic and interactive


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Web Page Tools

• JavaScript, VBScript, and Perl

– Scripting languages used to write Common

Gateway Interface (CGI) programs or scripts – Used to create customized, interactive Web

pages

– Inserted into the HTML document


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Web Page Tools

• Content Management System (CMS) tools

– Jooma

– Drupal

– Wordpress

– Among others.


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References:

• An I ntroduction to Web Design +

Programming by Paul S. Wang & Sanda S.

Katila• Programming the Web Using XHTML

and JavaScript

By Larry Randles Lagerstrom

lecture 1 internet website

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