Written by faculty at the Higher Colleges of Technology

1. CIS 1203
Web Technologies
Introduction to the Internet and the
WWW

2. Lesson Objectives
 Students should:
– Understand the Internet and its history
– Understand the WWW, its history and how it
relates to the Internet
– Discuss the evolution of the WWW
– Identify and describe the fundamental
technologies of the Web
– Explain how the Web works

3. Information Technology
 IT  all aspects of managing & processing
information using technology
– Mainly computers and computer networks:
• Hardware
• Software
• Connectivity (Networks)

4. Hardware
Software
Navigation software  Steer clear of danger
Image compression software  More image returns

5. Hardware
Software
Operating system  Control HW and other SW
Web browser Surf the net
Photo gallery  Organize photos
Text editor  Compose and manage text messages

6. Connectivity
 Computer networks and telecommunications
infrastructure allow multiple hardware
devices to connect and share data and
information
Transmits voice
and data to other
devices
Transmits
data back
to earth

7. Computer Networks
 A network is a group of two or more
computers connected
– Why connected?
• To communicate, share resources and exchange
information

8. Types Of Networks
 LAN
– Local Area Network
» Computers are connected in a confined geographical area
 WAN
– Wide Area Network
» Computers span a large geographical area

9. The Internet
 A network of networks
– A worldwide collection of computer networks, cooperating
with each other to exchange data using a common
software standard
 Multiple data systems
– Email
– FTP (File Transfer Protocol)
– TELNET
– The World Wide Web (WWW)
– And more

10. History of The Internet
 The Advanced Research Projects Agency (ARPA) -1957
– A Department of Defense project to establish US lead in science and
technology applicable to the military
 Operation ARPANET
– A need for a bombproof communications system
– Link computers together throughout the US
– Gradual shift from a military pipeline to communications tool for scientists
 In late 1980s, DOD decommissioned the ARPANET to NSF (National
Science Foundation) Network called NSFnet
– Large telecommunication companies created high speed data lines and
connected to NSFnet
 The rest is history…

11. But What is The WWW?
 Created in 1989 in CERN
 The “information superhighway”
– A method of posting and accessing interactive
multimedia information
 Hyper what?
– The WWW is based on a concept called
hypertext
• The organization of information units into
connected associations that a user can choose
to make (links)

12. Web 1.0
 Web pages connected together via hyperlinks
 Mostly static and very little interaction
between the user and the webpage
 Focus is companies that own create and own
their content

13. Web 2.0
 Dynamic web pages that are data-driven and
user-centric
 High level of interactivity with user-generated
content (blogs, forums, social networks, video
sharing, etc.)
 Rich interfaces made possible through AJAX
– AJAX  Asynchronous JavaScript And XML

14. AJAX Library Demo
 jQuery: http://jqueryui.com/

15. Mobile Web
 Web resources are being accessed via mobile
devices
 Companies are developing mobile versions for
their websites
 Mobile commerce is an emerging trend

16. The Client-Server Model
Internet
Server Side Client Side
Client-Server Model: describes the relationship between two computer
programs in which one program, the client, makes a service request from
another program, the server, which fulfills the request
HTTP request
HTTP response Web BrowserWeb Server

17. What is HTTP?
 HTTP (Hypertext Transfer Protocol) is the
foundation of data communication for the
WWW
 A protocol defines a set of rules that enable
effective communications between computers
 HTTP is part of a protocol framework called
the Internet Protocol Suite which includes
TCP/IP

18. TCP/IP
 Transmission Control Protocol (TCP):
– Establishes connections among sending and receiving Web computers
– Handles assembly of packets at point of transmission, and reassembly
at receiving end
 Internet Protocol (IP):
– Provides the Internet’s addressing scheme

19. Internet Protocol (IP) Addresses
 IPv4:
– 32-bit number
– Expressed as series of four sets of separate numbers
marked off by periods
• 201.61.186.227
• Class C address: Network identified by first three sets, computer
identified by last set
 New version: IPv6 has 128-bit addresses, able
to handle up to 1 quadrillion addresses (IPv4
can only handle 4 billion)
sbaserver1.sba.muohio.edu 134.53.40.2

20. Routing Internet Messages: TCP/IP

21. Web Browser Overview
 A tool for “traveling” the internet
 A “client” software for “surfing” the WWW
 Browser war
– Different vendors
– Non standard extensions
– Different viewing experience of the same web page
 Then came the standards
– World Wide Web Consortium (w3c)
• http://w3c.org
• Internet Explorer
• Safari
• FireFox
• Mozilla
• Opera
• Lynx

22. Web Browsers and Devices
The way a webpage is displayed depends on the
monitor size and screen resolution
Some browser might not support flash or other
multimedia objects
Some browsers are so small, the whole webpage
layout must be different

23. How Browsers Work
 Enter URL or click a link
 The browser breaks the address into 3 parts
1. Protocol
2. Server and domain name
3. The resource name (webpage)
1 2 3

24. How Browsers Work
 The browser then communicates with a
domain name system (DNS) server that
translates the domain name into IP address
DNS Server 1
Sorry I don’t know
this address. Let me
check another server
DNS Server 2
I found it. The IP
address is:
Du Web Server

25. How Browsers Work
 Your browser sends an HTTP request to the
server using its IP address
 Some level of authentication takes place
 The server sends the requested page coded in
HTML
 Your browser reads the markup of HTML and
interprets it into the web page that you view

26. Domain Names, DNS, and URLs
 Domain name
– IP address expressed in natural language
 Domain name system (DNS)
– Allows numeric IP addresses to be expressed in natural
language
 Uniform resource locator (URL)
– Address used by Web browser to identify location of
content on the Web
– E.g. http://hct-portal.hct.ac.ae/students

27. Top-Level Domain (TLD) Names
Domain Signifies Domain Signifies
aero Air-transport industry au Australia
biz Business organization br Brazil
com US commercial ca Canada
coop Coooeratives cn China
edu US educational de Germany
info Unrestricted fi Finland
gov US government fr France
mil US military gb Great Britian
museum Museums in India
name Individuals it Italy
net US network jp Japan
org US non-profit ru Russia
pro Professionals za South Africa

28. URL
 Uniform Resource Locator
http://samer.ecommerce.hct.ac.ae/fw/index.php
File Name
Path
Domain Name
Double slash means a
system address will
follow
Access method
or Protocol
A separator