Transcript Internet Fundamentals

E-commerce and Information Technology
in Hospitality and Tourism
Chapter 2
Internet Fundamentals
Copyright 2004 by Zongqing Zhou, PhD
Niagara University
2.1 Defining The Internet
 A global network of computers communicating with each
other using a common language--- A network of networks.
 Also referred to as the Information Super Highway, or
World Wide Web.
 Using the highway analogies has several advantages.
– it lays the foundation for later chapters when we talk about speed of
information transmission in the Internet.
– Information such as text, voice, graphics and videos are like
vehicles of all types traveling through the Internet. The more
vehicles traveling on a highway, the slower the speed.
– The wider the highway the more likely the vehicles will be able to
travel high speed. Telephone lines are like an old country path that
will not be able to accommodate large trucks (large chucks of
information such as multimedia digital signals).
2.1 Defining The Internet (cont.)
 Composed of two major parts:
– Hardware: Telephone networks, cables,
routers, computers, servers, and
satellites.
– Software: programs, applications, and
protocols which make communication and
transactions online possible.
Server
Figure 2.1
a simple internet
Computer
Person
Router
Router
Router
Server
Server
History of the Internet
 1960s Rand Corporation was entrusted to develop a
strategic communication system --- a loosely connected
command network, where any point in the network could
send or receive messages, which is the foundation of the
peer-to-peer system.
 The idea is to decentralize the information control. Today,
the idea is still very much alive and in fact explains why the
Internet is so popular and widely spread.
 Late 1960s saw the construction of such a system funded
by ARPA (Pentagon’s Advanced Research Projects
Agency)
 This system or network came to be called ARPANET.
 Communication between networks was made possible by
the Internet Protocol or “IP”.
History of the Internet (cont.)
 ARPA developed the transmission control protocol/
Internet protocol or “TCP/IP” to connect
incompatible computers and networks used by
government agencies, the military, government
suppliers and research institutions.
 TCP converts data into packets which are sent
across the transmission lines to the next computer
whose TCP reconverted packets into data it can
read.
History of the Internet (cont.)
 In Oct 1972, the use of the Internet spread
quickly after its first demonstration to the
public
 Email was introduced in 1972, almost 20
years before the WWW
 1990, ARPANET, the first Internet network,
ceased to exist.
 By 1991, the Internet had become an
important means of communication.
2.3 Internet Basics
The Word Wide Web (1)
 First, there is the Internet before the WWW.
 Secondly, the Internet before the WWW uses a
text-only interface, display on your computer
screen.
 Thirdly, today most people use the two terms (the
Internet and (WWW) interchangeably
 But technically speaking, the two terms are not
synonymous. The Internet and the Web are two
separate but related concepts.
 The Internet is a massive network of networks, a
networking infrastructure.
The World Wide Web (2)
 In 1989 Time Berners-Lee invented the World
Wide Web.
 In 1994, WWW gained wide spread popularity.
 The Web adds a graphical interface to the Internet
that made gathering and retrieving information
easier.
 The Web also made presentation of voice, data,
graphics, and video possible and attractive.
 Its hyperlink capability made possible by the
HTML, the simple programming language for the
Web.
The World Wide Web (3)
 The World Wide Web, or simply Web, is a way of
accessing information over the medium of the
Internet.
 It is an information-sharing model that is built on
top of the Internet.
 The Web uses the HTTP protocol, only one of the
languages spoken over the Internet, to transmit
data. Web services, which use HTTP to allow
applications to communicate in order to exchange
business logic, use the Web to share information.
The World Wide Web (4)
 The Web also utilizes browsers, such as
Internet Explorer or Netscape, to access
Web documents called Web pages that are
linked to each other via hyperlinks.
 Web documents also contain graphics,
sounds, text and video.
The Word Wide Web (5)
 The Web is an abstract, imaginary cyberspace
super-imposed on the infrastructure of the
Internet.
 The Web is just one of the ways that information
can be disseminated over the Internet. The
Internet, not the Web, is also used for e-mail,
which relies on SMTP, Usenet news groups,
instant messaging and FTP. So the Web is just a
portion of the Internet, albeit a large portion, but
the two terms are not synonymous and should not
be confused.
The Word Wide Web (6)
 The WWW is a component of the Internet, but it is
different from it in several aspects:
– It uses a graphical based interface, enabling color and
graphical displays
– Its information uses texts that are marked up (HTML)
– And thus requires a special decoding device (browser)
– Servers with special programs are needed (Web
servers)
– The information contained in a Web document can be
hyperlinked.
The Word Wide Web (7)
 The main components of the Web is the
Web Servers and browsers.
– Web servers are computers that store the
data in HTML to be retrieved by the Web
users as Web pages.
The Browser
 Is the interface that allows one to see
graphics and text files that make up the Web
and the Internet.
– An interface is a program to translate and
present information on the computer screen.
 The browser is like a detective’s microscope
or decoding device. The browser is used to
display the HTML (Hypertext Markup
Language) as the standard publication texts.
The Browser
 It is important to point out that there are
other browsers than Microsoft Internet
Explorer.
 Telnet is the ‘browser’ to the Internet before
the WWW as the browser of today to the
Web. It is the interface for text-based
communication between computers on the
Internet
The Browser (cont.)
 Berners-Lee created the first browser called
the World Wide Web
 1993 saw the first commercialized browser,
Mosaic, developed by the National Center
for Supercomputing Applications.
The Browser (cont.)
 Today’s most popular browsers are Internet
Explorer and Netscape Navigator.
 Two concepts on how the web works
include:
– Universal resource locator (URL), the address
of a webpage located anywhere on the Web.
– Hypertext transfer protocol (HTTP), a method of
accessing the Internet.
Hypertext and HTML
 Hypertext is an item designated as a
hyperlink, which, when clicked, will take the
user to another page within that site or to
another page or imaging on another site.
 A hyperlink can be text or a graphic or any
item designated as such.
 An HTML document is a plain text document
that is “marked up” with codes for browser
display.
HTML
 HTML: Hypertext Markup Language) is a
collection of platform-independent styles
indicated by markup tags that define the
various components of the w Web
document.
 In an HTML document, differrent codes and
symbols are used to indicate different text
styles and appearance when viewed by a
browser.
Table 2.1
Common Tags Used in HTML
<html>

<head>

<TITLE>A Simple HTML Example</TITLE>

</head>

<body>

<H1>HTML is Easy To Learn</H1>

<P>Welcome to the world of HTML.

This is the first paragraph. While short it is

still a paragraph!</P>

<P>And this is the second paragraph.</P>

</body>

</html>
**The required elements are the <html>, <head>, <title>, and
<body> tags (and their corresponding end tags).
E-Mail
 Consists of electronic transmissions of a
digital message over the internet. The
message can be as follows, but not limited
to:
– Letters
– Notes
– Documents
– Images
– Files
– software
E-Mail (cont.)
 Elements of an email address:
– A screen name
– A domain
– An extension
 The domain and the extension are
commonly referred to as the domain
name
Mailing List
 Also known as an email discussion group, is
a list of email addresses that is used to send
messages to many people at the same time.
 A Virtual Community: virtual because they
exist only in cyberspace and a community
because they share a common interest.
 The list owner controls the list and rules for
each of the subscribers.
 Mailing List is deliberately capitalized here
to distinguish it from traditional mailing list.
Mailing List vs. mailing list
1. Requires a special
management
software
2. Subscription based
3. Enables interactive
communication
4. Highly interest based
1. Users common e-mail
software
2. Can be assembled by
anyone
3. One way
communication
4. Need not be interest
based
Table 2.2
A Mailing List and its Basic Elements
List Name
1. Purpose
2. List Type
3. Subscription
4. Archive
5. Created
6. Owner
7. To Join
8. To Post
9. Stats
Adventure (Reno)
1. An adventure forum for passionate
and adventurous people: sports,
travel, global escapes.
2. Unmoderated discussion
3. Does not require owner approval
4. Readable by anyone
5. Mar. 05, 1999
6. Reno marioni
7. Subscribe here, or send an e-mail to
[email protected]
8. Send mail to [email protected]
9. 62 subscribers/1 messages per week.
Usenet, Newsgroups, and
Discussion Forums
 Usenet is a distributed bulletin board system
a BBS, a users’ network.
 A newsgroup can also be considered a
discussion forum.
 Usenet uses a traditional indexing and
cataloging system and the top level of the
discussion is called a category.
– For example “alt” in which you can find
alt.travel.canada
Table 2.3
The INFOTEC-TRAVEL Mailing List
1.
2.
3.
4.
5.
6.
7.
Mailing List Name 1.
2.
Description
To subscribe
3.
To post a message
To unsubscribe
For more information
4.
List owner e-mail
INFOTEC-TRAVEL
Information Technology in Travel
and Tourism Worldwide
Send a message to [email protected]
with only “subscribe infotec-travel
your name” in the message body.
Send the message to [email protected]
5. Send a message to [email protected]
6. www.infotec-travel.com
7. [email protected]
Java and JavaScript
 Java is a simple object oriented
general purpose programming
language.
 Java supports the creation of virusfree, tamper-free systems based on
public-key encryption, which is an
online security system for transferring
messages.
Java and JavaScript (cont.)
 Major Benefits:
– Quick start- easy to learn
– Write less code- smaller program
– Write better code- introduce fewer bugs
– Develop programs more quickly- writes fast,
fewer code lines.
– 100% pure java- keep your program portable
– Run anywhere
– Easily distributed.
Java Continued
 Java programs:
– Applications- stand-alone programs, that
can execute programs written in the java
language.
– Applets- adhere to a set of conventions
that let it run within a java capable
browser.
 JavaScript is an extension of HTML which
allows the author to incorporate some
functionality into their webpage.
 .
Java (cont.)
 Three Environments:
–Server-side scripting language
–Embedded language in HTML
–Embedded language in the browser