Transcript Who uses the Internet

Understanding the Internet
Chapter 1
Learn how to…
• Define the Internet, describe how large the
Internet is, and compare its explosive growth.
• Identify the most popular Internet services.
• Describe underlying concepts of the Internet.
• Define how the Internet impacts everyday life.
• Provide a brief history of the Internet.
• Describe efforts under way to improve the
Internet.
CIW
• CIW stands for Certified Internet
Webmaster.
• To certify, you have to pass an exam
proctored by an independent testing firm.
• The exam covers:
– Internet Fundamentals
– Web Page Authoring Fundamentals
– Networking Fundamentals
Defining the Internet
Defining the Internet
• The Internet is a worldwide connection of more
than 171 million computers.
• It uses the Internet Protocol (IP) to
communicate.
• Invented for the Advanced Research Projects
Agency (ARPA) of the U.S. Department of
Defense.
• Used to create a decentralized network that
could continue to function even if part of it was
taken out by a nuclear bomb.
Traffic on the Internet
• Traffic volume is depicted by the lines.
– Purple lines indicate 0 bytes
– White lines indicate 100 billion bytes
Who uses the Internet
• People
from all
walks of
life use the
Internet.
• The
Internet is
growing
at a
phenomen
al rate.
Identifying Eleven Popular
Internet Services
Internet Services
The most popular services on the Net are:
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Electronic Mail (e-mail).
Listserv
Newsgroups
Chat
Videoconferencing
File Transfer Protocol (FTP)
Multimedia Streaming
World Wide Web
Rich Site Summary (RSS)
Blogging
Electronic Mail (e-mail)
• Mails queue
up in your
mailbox.
• Users read
and respond
at their
convenience.
Listserv
• Listserv stands for List Server
• It works like an electronic mailing list.
• Users subscribe and then receive a copy of any
e-mail sent to the list.
• Electronic magazines (e-zines) are distributed
using listservs.
Newsgroups
• Newgroups
are an
electronic
bulletin-board
service.
• They contain
discussions on
any topic.
• A newsreader
is used to
access a
newsfeed.
Chat
• Real-time communications in chat rooms
• Users type messages back and forth.
Instant Messaging (IM)
• Instant Messaging
(IM) allows you to
keep in contact with
friends or associates.
• When someone on
your buddy list wants
to talk to you, an
instant message
appears on your
screen.
Video Conferencing
• Video conferencing uses a video camera
and a microphone to allow people to see
and hear each other.
• Because of high bandwidth demands, it
is not yet as popular as text-based
messaging.
FTP
• File Transfer Protocol (FTP) is used to transfer
files over the Internet from one computer to
another.
Multimedia Streaming
• Streaming is the digital transmission
of multimedia content in real time over
the Internet.
• Only the amount of data needed to
continue playing is stored in a buffer
in memory.
• Many radio stations stream their
programming live over the Internet.
World Wide Web (WWW)
• A hypertext system
that allows
documents to be
shared over the
Internet.
– Hypertext refers
to text that has
been linked.
Browsers
• Mosaic is a graphical user interface that
made the Internet extremely easy to use.
– Web pages may display pictures.
– Links to audio and video may be included.
• Netscape Navigator was soon released
and became the most popular Web
browser.
• Microsoft introduced Internet Explorer.
W3C
• W3C is the World Wide Web
Consortium.
– It coordinates the research and development
of new standards and features for the Web.
Rich Site Summary
• Rich Site Summary (RSS) allows
syndicating of a Web site in a form that
can be registered with an RSS publisher.
• Other sites can subscribe to the Web site
to access the RSS feed from an RSS
publisher.
• Uses eXtensible Markup Language
(XML).
Blogging
• Blog is short for Web log.
– A Web-accessible log is written by someone
who wants to chronicle activity related to a
given topic (often personal).
– It is essentially keeping your diary online.
Describing the
Infrastructure of the
Internet
Client-Server Computing
• The Internet is made up of computers that
send and receive information in a clientserver environment.
– Servers send information.
• Servers devoted to sending Web pages are called
Web servers.
– Clients receive information.
• When you search the Web using a Web browser,
your computer is a client.
TCP/IP
• Information is transmitted over the Internet
in units called packets.
• TCP and IP are two protocols required to
send packets.
• Transmission Control Protocol (TCP)
is used to break large packets into smaller
ones.
• Internet Protocol (IP) handles the
addressing and routing of packets.
IP Addresses
• IP uses IP addresses to identify
computers.
• Each packet contains the source and
destination IP addresses.
• IP addresses consist of four 8-bit bytes
ranging from 0 to 255.
• IP addresses are often expressed in
dotted quad notation.
– Example: 140.147.249.7
DNS
• DNS stands for Domain Name System.
• DNS allows you to use alphanumeric
characters instead of numbers for
IP addresses – making it easier to
remember them.
– For example, www.loc.gov can be used
to reach the Library of Congress instead
of remembering 140.147.249.7.
FQDN
• A complete DNS address is called a Fully
Qualified Domain Name (FQDN).
– FQDNs have the format
hostname.registered-domain-name.top-level-domain.
Top-Level Domains
• Top-Level Domains (TLD) in the United States
include:
• In the rest of the world, TLDs are usually
country codes.
TLD Country Codes
Domains
• Domain refers to the network to which a
computer is connected.
• Host name refers to the computer itself.
• A domain can be subdivided into subdomains.
• Possible formats are:
– hostname.registered-domain-name.second-leveldomain.top-level-domain
– hostname.subdomain-name.registered-domainname.top-level-domain
ICANN
• ICANN stands for Internet Corporation
for Assigned Names and Numbers.
– Assigns domain names, IP addresses,
protocol parameters, and port numbers.
Intranet
• An Intranet is a network that uses the
TCP/IP protocols to provide private
services within an organization.
– It uses Internet technology within a private
network.
Extranet
• Extranet refers to Internet resources that
are beyond the reach of the public and
require a logon name and password to
access.
Changing the World via the
Internet
Convergence
• Convergence is the process of unification
that digitalization causes by enabling all
the world’s traditional ways of
communicating to work over a common
communications medium on the Internet.
• Digital divide refers to barriers faced by
the unconnected.
Mergers and Alliances
• Corporate mergers and alliances have
occurred as a result of the Internet and the
digitalization of communication.
Telecommuting
• Telecommuting is the act of working from home
by using computers, dial-up modems, or
broadband network connections, and fax
machines to perform work that formerly required
a person to travel physically to work.
– A person who telecommutes is a teleworker.
Business & Advertising
• The Internet has become a utility for
businesses to advertise and market their
products.
– Companies offer free services to entice
people to visit their Web site more often.
– Pop-under (appear under an opened Web
page) and pop-up (appear on top of an
opened Web page) advertises are very
common.
Online Shopping
• Teleshopping is purchasing products
online.
– Fifty-seven percent of adults shopped online
in 2001.
Online Banking
• Now, you can pay your bills online with
online banking.
• You can also invest your money and
manage your portfolio online.
Government Services
• The Net
makes
government
services
more widely
available.
Politics
Information Warfare
• Information warfare is an electronic
attack or invasion of computer networks.
– The Department of Defense is prepared to
disconnect its worldwide network from the
Internet if necessary.
Homeland Security
• The USA Patriot Act gives wide latitude to
the government in using Internet
surveillance systems.
– Terrorists use the Internet to hide secret
messages.
– The FBI uses a system called Carnivore
to intercept suspicious e-mails.
Electronic Publishing
• Electronic book (eBook) technology
allows publishers to sell books in
electronic format.
– eBooks are in a full text searchable format.
Television & Entertainment
• The Internet competes with television for
people’s free time.
• You can find TV listings on the Internet.
• Interactive TV merges the Internet and
television.
– Play along with Wheel of Fortune or Jeopardy.
– Vote for your choice on Judge Judy.
Teaching and Learning
• Computer-based learning strategies lead
to faster and better learning.
• Learning can be customized to the
individual student.
Tracing the History of the
Internet
Origin of the Internet
• The Internet began when the Advanced
Research Projects Agency (ARPA) of the
Department of Defense (DoD) began a
network called ARPANET in 1969.
– DOD wanted a network that could survive
a nuclear attack without stopping
communication.
Colleges and Universities
• In the 1970s, colleges and universities
connected to ARPANET using IP.
– In 1983, the military part broke off and
became MILNET.
• In 1986, the National Science Foundation
(NSF) began NSFNET to connect the
nation’s five supercomputer centers.
– In 1991, commercial entities were allowed
to connect to NSFNET.
Internet Backbone & DNS
• In 1995, NSFNET reverted to research;
the Internet backbone traffic began to be
routed through network providers.
• In 1998, the U.S. government turned over
management of the domain name space
from InterNIC to ICANN.
Internet2
• Declining cost and explosive growth in
using the Internet has spurred research
into a faster network called Internet2.
Looking Into the Future of the
Internet
Improving the Infrastructure
• Multicast backbone (MBONE) is a
network of computers on the Internet
specifically designed for the transmission
of simultaneous live video and audio
broadcasts.
Streaming Media
• Streaming media network vendors bring
uninterrupted audio and video streams to
end users.
– Streaming media is fed directly to edge
servers located near local ISPs.
Streaming Media
Internet2
• Internet2 is a project to create a higherspeed Internet.
– Utilizes high-speed connection points called
gigapops.
– Resource Reservation Protocol (RSVP)
reserves bandwidth from workstation to host
computer.
– Internet Protocol version 6 (IPv6) allows users
to assign priorities to certain traffic.
– Multicast increases multimedia throughput.
Wireless Communications
• Wireless technologies no
longer require a cable to
connect to the Internet.
– Motorola’s 200 Smartphone
brings the Internet to the palm
of your hand.
Bluetooth
• Bluetooth is an
emerging standard for
high-speed wireless
communication.
– It enables
communication among
mobile computers,
telephones, handheld
devices, and the
Internet.
Wi-Fi
• Wi-FI is a trade name based on IEEE
802.11 specification for wireless local area
networking.
• Wi-Fi access points are called HotSpots,
an area over which you can connect.
• FreeSpots are locations that offer free
wireless Internet access.
– Examples: Hotels, coffee shops, restaurants,
and airports
IP Telephony
• IP telephony merges the public switched
telephone network (PSTN) with IP.
– It converges voice, video, and data into one
network using Voice-over IP (VoIP).
– Microsoft’s Telephone Application Program
Interface (TAPI) enables Windows users to
use IP telephony.
– IP telephone calls are much cheaper than
normal long-distance calls.
Personal Digital Assistants
• Personal digital assistants (PDAs) are
portable, handheld computers.
• Windows CE
– A compact module
version of Microsoft
Windows
– Example:
Toshiba’s
PocketPC
• Palm OS
– Created by Palm, Inc.
specifically for a small
device
Artificial Intelligence
• Artificial Intelligence (AI) includes:
– Voice recognition
– Text-to-Speech conversion
– Foreign language translation
– Image recognition
– Bots
Voice Recognition
• Voice recognition allows software to
recognize your voice and respond.
– Voice-controlled Web surfing, legal dictation,
environmental control systems, and word
processing.
Text-to-Speech Conversion
• Text-to-speech conversion allows you to
hear conversations and see them.
Foreign Languages
• Foreign language translation can translate
Web pages, e-mail, chat, and other
documents between languages.
Image Recognition
• Image recognition software can compare
images using a visual template.
– Search for images based on visual properties.
Bots
• Bots, short for robots, are software
applications programmed to act as
intelligent agents that go out on the
network to find or do things for you.
Digital TV and Video
• Digital televisions provide a highresolution display screen that can
integrate computer data, Web pages,
and television broadcasts.
HDTV
• High-Definition Television (HDTV)
is based on:
– MPEG digital video compression
– Transmission in packets that permit any
combination of video, audio, and data
– Progressive scanning for computer
interoperability up to 60 frames per second
(fps) at 1920 × 1080 pixels
– CD-quality digital surround sound using
Dolby AC-3 audio technology
MPEG Digital Video
• The Motion Pictures Experts Group
(MPEG) developed the MPEG standard.
– Eliminates redundant data in images.
– Uses delta-frame encoding to record only
the changes from one frame to another.
MSN TV
• An MSN TV Internet
receiver is a device
that combines your
telephone with the
video signal on your
TV or VCR.
– See Web pages on
your TV screen.
– Sometimes called
telecomputer.
Ultimate TV
• UltimateTV allows you to record your
favorite shows without a VCR, pause live
television, create your own TV program
line-up, and instantly replay anything you
see on TV.
Digital Hubs
• Your personal PC will become a digital hub that
coordinates all of the electronic devices in your
home.
– Play music in other rooms from your PC.
– Distribute video streams to receivers throughout
your home.
– Print digital camera photos without plugging
anything.
– Keep an eye on your home while you are away
over the Internet.
– Remote control all of your home appliances.