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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
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