Transcript Internet and Web

The Internet and
World Wide Web
Objectives
Discuss how the Internet works
Understand ways to access the Internet
Identify a URL
Describe the uses of e-commerce
Identify the tools required for Web publishing
Explain how e-mail, FTP, newsgroups and message
boards, mailing lists, chat rooms and instant
messaging work
The Internet or the Net
A collection of
computers and other
devices connected
together via
communications
 Modems
 Cables
 Telephone lines
 Satellites
A worldwide collection
of networks that links
millions of businesses,
government agencies,
educational
institutions, and
individuals
The Services on the Internet
instant messaging
e-mail
Web
message board
chat
file transfer
History of the Internet
APRANET
 ARPANET: Networking project by
Pentagon’s Advanced Research Projects
Agency (ARPA)
 Goals:
 To allow scientists at different locations to
share information and work together on
military and scientific projects
 To function even if part of the network were
disabled or destroyed
 Became functional in 1969
ARPANET
A host node or a host
 Any computer that directly connects to a
network
 Often stores and transfers data and messages
 Provides network connections for other
computers
 Four original nodes on ARPANET
 UCLA
 UC – Santa Barbara
 Stanford Research Institute
 University of Utah
How has this network grown?
 1969: Four host nodes
 1984: More than 1,000 host nodes
 2004: More than 100 million host nodes
What is NSFnet?
 The National Science Foundation’s
network
 Five supercomputer centers
 Connected to ARPANET in 1986
NSFnet + APRANET = The Internet
Who provides the structure for
the Internet today?
Networks from corporations, commercial
firms, and other companies
Telephone companies
Cable companies
Satellite companies
Government
Who controls the Internet?
 The Internet is a public, cooperative, and
independent network
 No single entity controls or owns the
Internet
 Several organizations advise and define
standards
 W3C – oversees research and sets
standards and guidelines
 Internet 2 – develops and tests advanced
Internet technologies
Internet service provider (ISP)
 A business that has a permanent Internet
connection
 Provides temporary connections to individuals
and companies for free or for a fee
 Regional ISP - Provides access to the Internet
through one or more telephone numbers local
to a specific geographic location
 National ISP - Provides local telephone
numbers in most major cities and towns
nationwide
How can you connect to the Internet?
High speed connection
Connect to service provider through a high-speed
connection line leased from local telephone company
Dial-up access
Computer, modem, regular telephone line
Dial into an ISP
Newer high-speed technologies
DSL
Cable modem
Three parts of an Internet connection
Server
• Computer that
•
•
manages the
resources on a
network
Provides a
centralized storage
area for resources
Also called a host
computer
Backbone
• Inner structure
•
of the Internet
Communications
lines that carry
the heaviest
amount of traffic
Client
• Computer
that can
access the
contents of
the storage
area on the
server
Internet protocol (IP) address
 Number that uniquely identifies each
computer or device connected to the
Internet
 Four groups of numbers, each
separated by a period
 Number in each group is between 0
and 255
 199.95.72.10
What is a domain name?
 Text version of an IP address
 Components are separated by periods
 Each domain name represents one or more
IP addresses
 199.95.72.10
 www.course.com
A top-level domain (TLD) abbreviation
 Identifies the type of organization associated
with the domain
 Sometimes called dot com when TLD is com
What systems control domain names?
Internet Corporation for Assigned
Names and Numbers (ICANN)
Group that assigns and controls TLDs
Domain name system (DNS)
stores the domain names and their
corresponding IP addresses
DNS server
Translates the domain
name into its associated IP
address
World Wide Web (WWW) or the Web
 A worldwide collection of electronic
documents
 Each document on the Web is called a Web
page
 Can contain text, graphics, sound, and
video
 Can contain built-in connections to other
documents
 A Web site is a collection of related Web
pages
What is a Web browser?
 Software program that allows you to
access and view Web pages
 Some popular browsers

Firefox (47.4%)

Internet Explorer (39.3%)

Chrome (7%)

Safari (3.3%)
What is downloading?
The process of receiving
information, such as a Web
page, onto your computer
from a server on the Internet
Can take from a few seconds
to several minutes
What is a hyperlink?
 Also called a link
 Built-in connection
to another related
Web page or part
of a Web page
 Allows you to
obtain information
in a nonlinear way
How can you identify a link?
 Link can be a word, phrase, or image
 Text links usually are underlined or in a color
different from the rest of the document
 A graphical link may change its appearance
when you point to it

The shape of the pointer on the screen changes
to a small hand with a pointing index finger when
you position it on a link or point to the link

Click the link to activate it
Uniform Resource Locator (URL)
 Browser retrieves a Web page by using the URL
 Also called a Web address
http://www.nationalgeographic.com/travel/index.html
address
text box
What are the parts of a URL?
protocol
domain name
path
filename
http://www.nationalgeographic.com/travel/index.html
Click to view Web Link
then click URLs
Next
p. 2.13 Fig. 2-10
What is a search engine?
 A software program you can use to find
Web sites, Web pages and Internet files
What is a portal Web page
 Often called a portal
 Offers a variety of Internet services
from a single, convenient location
What services are often found on a portal?
search
engine
local ,
national, and
worldwide
news
free
personal
Web pages
e-mail
sports and
weather
stock
quotes
instant
messaging
maps
newsgroups
or message
boards
reference
tools
shopping
malls and
auctions
chat rooms
calendars
A Graphic on the Web
A digital representation of information such as a drawing,
chart, or photograph
What is audio? What is MP3?
 Music, speech, or
any other sound
Streaming audio
enables you to
listen to the sound
as it downloads
 A popular
technology that
compresses audio
 Reduces an audio
file to about onetenth of its
original size
What is video?
 Consists of
 MPEG standard:
full-motion
Video files that you must
images that
download completely
are played
before you can play them
back at
on the computer
various speeds  Streaming video: allows
 Most video
you to view live video
also has
images as they download
accompanying
 RealVideo
audio
 Windows Media Player
What is electronic commerce?
 A business
transaction that
occurs over the
Internet
 B2C: Sale of
goods to the
general public
 B2B: Businesses
providing goods
and services to
other businesses
What are some features of
e-commerce?
 Electronic storefront
 The place where a customer visits an
online business
 Shopping cart
 Allows the customer to collect
purchases
Web page authoring
 HTML (hypertext markup language)
 A set of special codes that format a
file for use as a Web page
 Created with either:
 Word processing package
 Web page authoring software
What is a plug-in?
 An additional program that extends the
capability of a browser
How do you deploy a Web site?
Locate a Web
server to store your site
• Provided by many ISPs
at no additional cost
• Provided by a Web
hosting service for a
monthly fee
Upload, or copy,
the site to the
Web server
What is e-mail?
 The transmission of messages and files via a
computer network
 Use an e-mail program to work with messages
create
send
forward
store
receive
print
delete
What is File Transfer Protocol (FTP)?
 An Internet standard that allows you to
upload and download files with other
computers on the Internet File Transfer
Protocol
What is instant messaging (IM)?
A real-time Internet communications service
 Notifies you when one or more people are
online
 Allows you to exchange messages or files
or join a private chat with them