Transcript File

APPLICATIONS & IMPLICATIONS OF
INFORMATION TECHNOLOGY &
COMMUNICATIONS TECHNOLOGY
Internet & Communications Technology
Internet & Communications Technology
On completing Section 4, you should be able
to:
 Use terms associated with data communications &
networks
 Distinguish among Internet, Intranet & Extranet
 Explain concepts associated with the internet
 Describe measures to secure data & maintain data
integrity
Internet & Communications Technology
Today’s class will cover the following objectives:
 Explain concepts associated with the internet
 Describe measures to secure data & maintain data
integrity
Internet & Communications Technology
Concepts associated with the Internet:
Electronic Mail (E-mail):
 Almost instantaneous transfer of text and video
messages from one computer or device to another ,
typically over the internet.
 Consists of 2 parts: message header and message body
 Message header contains control information such as
email addresses (originator & recipient(s)), subject
header field
 List some advantages and disadvantages of e-mail.
Internet & Communications Technology
Electronic Mail (E-mail):
 Advantages:
 Immediate sending and receiving of mail as opposed to snail-
mail
 E-mails do not need to be as structured or formal as typical
letters.
 No need for stamps, envelopes, paper, or going to a post
office.
 Disadvantages:
 Not everyone has access to a computer or software application
to use the e-mail facility
 Emails are not as private as personal letters.
 Replies are dependent on the recipient accessing the e-mail
and reading the message
Internet & Communications Technology
Newsgroups:
 Online bulletin boards
 Discussion group maintained on the Internet where
people leave messages (posting) on topics of interest
for other participants to read
 Some newsgroups are ‘moderated’ (a person or group
decides which postings will become part of the
discussion) and others are ‘un-moderated’ (everything
posted becomes part of the discussion).
 What are some examples of newsgroups?
Internet & Communications Technology
Internet Relay Chat (IRC):
 Form of real-time Internet text messaging (chat),
similar to a chat room
 Mainly designed for group communication in
discussion forums, called channels
 Also allows one-to-one communication via private
messages
 Examples: mIRC, XChat and ChatZilla, MSN
Messenger Service
Internet & Communications Technology
Telnet
 User command as well as a protocol for accessing
remote computers.
 With Telnet, an administrator or another user can
access someone else’s computer remotely with
whatever privileges that have been granted.
 Other protocols, such as FTP and HTTP allow the user
to request specific files from remote computers, but
not to be logged on as a user of that computer.
 Program developers and anyone with the need to use
specific data or applications would use Telnet.
Internet & Communications Technology
File Transfer Protocol:
 Standard Internet Protocol used as the simplest way to
exchange files between computers on the Internet.
 Internet equivalent of a file server
 Commonly used to download programs and other files
to your computers from other servers.
 Also used to transfer Web page files from their creator
to the server for all users of the Internet to view.
 Examples are BitTorrent, SFTP (Simple File Transfer
Protocol), AFP (Apple Filing Protocol)
Internet & Communications Technology
Web Browser:
 Program that allows users to view and explore
information on the World Wide Web
 Examples of web browsers: Microsoft Internet
Explorer, Mozilla Firefox
Web Server:
 Computer set up with software and networking
capability to deliver web pages on the Internet
 Processes document requests
 Examples: Apache, IIS
Internet & Communications Technology
World Wide Web:
 Leading information exchange service of the Internet
 Also thought of as an electronic library
 Invented at CERN, a nuclear physics lab located in
Switzerland
 Users can access a vast array of documents connected
to each other via hyperlinks (written in HTML format)
 Also contains image, sound and video documents
 It is relatively easy to use (point and click graphics)
Internet & Communications Technology
HTTP (Hypertext Transfer Protocol):
 Application layer protocol
 Used for retrieving hypertext documents
 HTTP is a request/response standard similar to clientserver methodology.
 The client submits HTTP requests and the server
responds by producing HTML files and images
Internet & Communications Technology
HTML (Hyper Text Markup Language)
 Predominant markup language for web pages
 Markup language – coding system specifying the layout
and style of a document
 Provides a means to create structured documents
(follows the rules for creating headings, paragraphs,
lists, links, etc.)
 Allows images to be embedded
 Can be used to create interactive forms
 Filename extension: ‘.html’ or ‘.htm’
Internet & Communications Technology
XHTML (Extensible Hyper Text Markup Language)
 Mirrors or extends versions of the HTML
 File extensions: ‘.xhtml’, ‘.xht’, ‘.xml’
Internet & Communications Technology
Web Page:
 Document or resource of information suitable for the
World Wide Web
 It can be accessed via a web browser
 Usually in HTML or XHTML format
 Provides navigation to other web pages via hypertext
links (hyperlinks)
 Web pages may be retrieved from a local computer or
from a remote web server
Internet & Communications Technology
Website:
 Collection of related web pages, images and video
addresses relative to a common Uniform Resource
Locator (URL).
 All publicly accessible websites make up the World
Wide Web.
 Some websites require a subscription to view their
content.
 Websites can be personal, commercial, governmental,
or non-profit organization.
Internet & Communications Technology
URL (Uniform Resource Locator)
 Unique Internet address assigned to a web document
by which it can be accessed by all web servers.
 First part of the address specifies the application
protocol being used (http:// or ftp://)
 Second part of the address provides the IP address or
the domain name of the location.
 Example: http://www.google.com
Internet & Communications Technology
URL (Uniform Resource Locator)
Symbol
Meaning
//
Gives the path to the computer on which the resources are stored
/
Shows the exact location of where resources are located
http
Tells you that this is a website. Http is a set of rules to show web
pages on a computer
ftp
Tells you that this is not a website, but can allow you to transfer
files across the Internet
.com
Indicates a commercial organization
.html
Indicates a file that contains hypertext: that is, a web page
.edu
Indicates a university
.org
Indicates some type of organization
.gov
Indicates a government department
.uk OR .tt
Indicates the country, e.g., United Kingdom OR Trinidad
Internet & Communications Technology
Blogging
 Personal online journal that is frequently updated and
intended for the public viewing
 Series of entries entered posted to a single page with
the most recent entry appearing first.
 Readers can also leave comments on entries.
 Entries are usually in the form of text. However, entries
can be in the form of graphics or videos.
Internet & Communications Technology
Podcasting
 The term ‘Podcast’ is combination of ‘iPod’ and
‘broadcasting’
 Refers to viewing and listening to audio and video files
from the Internet.
 Files can be downloaded from the Internet to PCs or
portable devices such as iPods.
 They are distributed in ‘episodes’, meaning new
podcasts are available on a regular basis.
 Podcasts can also be downloaded and viewed while ‘on
the go’.
Internet & Communications Technology
Bulletin Board
 Facility on the Internet where persons can post
messages on a particular topic.
 Other people can reply to messages at a later date.
 Everyone with access to the bulletin board can view
posted messages and replies.
Internet & Communications Technology
E-Commerce (Electronic Commerce)
 Consists of buying and selling products and services
via the Internet
 Can be from business-to-business or business-toconsumer
 Examples of companies that use e-commerce are
Amazon and Dell
Internet & Communications Technology
E-Learning (Electronic Learning)
 Used to define a program of study where students
access study material via the Internet.
 Use of computers as a key component of the
educational environment.
 Some advantages of e-learning:
 Increases access to many sources of information
 Convenient and flexible to learners
 Allows persons to develop skills and competencies with
respect to computer literacy.
Internet & Communications Technology
VoIP (Voice-over IP)
 Internet Protocol used to convert sound of voice into
digital form and transmit it over the Internet.
 Most popular example today is Skype.
 Major advantage: some users avoid paying
international call charges.
 Blackberry phones use VoIP to access e-mail, IMs,
browse Internet.
Internet & Communications Technology
Data Security
Definition:
Computer Security:
 Protection of hardware and software resources against
their accidental or deliberate damage, theft, or
corruption.
Data Security:
 Protection of data against intentional or accidental
damage.
Internet & Communications Technology
Data Security
Organizations invest a lot to ensure that data stored in
their information systems are secure against various
hazards (natural, man-made).
Threats can be from external or internal sources, as
well as from deliberate or accidental causes.
Internet & Communications Technology
Data Security
Sources
Accidental
Deliberate
External
• Natural Disasters – floods,
hurricanes, earthquakes,
volcanoes (natural
phenomena)
• Electrical power surges &
spikes – changes in electrical
power can cause damage to
computer hardware, software &
stored data files.
• Hackers – computer users
attempt to access data files &
records using communication
networks to:
- plant viruses,
- access sensitive data files,
- divert electronic financial
transactions for personal gain
• Industrial espionage
• Physical theft of hardware &
software by break-ins
• Terrorist activities – bombings,
arson
Internet & Communications Technology
Data Security
Sources
Accidental
Deliberate
Internal
• Clerical Errors – errors in data • Disgruntled employees with a
entry
grudge against the company
• Files accidentally erased or
could attempt to damage
corrupted
critical data using their
• Internally produced software
knowledge of system
(proprietary software) may be
operations.
flawed & may result in
• An employee may try to
damaged data.
fraudulently obtain money
• E-mail attachments
using the company’s name (e.g.,
containing viruses may be
receiving payments for nonopened & spread throughout
existent orders)
the computer network &
damage data.
Internet & Communications Technology
Data Security Measures
There are 2 general categories of securing data:
1. Software restrictions (protecting files & databases)

Passwords, Encryption, Virus protection, Firewall
2. Physical access restrictions
 Biometric systems, Guards, Locks, Fire/Water proof
cabinets, UPS (Uninterruptible Power Supply)
Internet & Communications Technology
Data Security
Viruses:
There are three main types:
 Those that infect program files:
 Virus attached to program code; when program is
loaded, so is virus.
 Those that infect system or boot files:
 Virus is loaded into memory and is able to run whenever
the computer is on.
 Macro Viruses:
 Carried by a document file & is executed when the
document is opened