The Internet andWorld 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 messageboards, mailing lists, chat rooms and instantmessaging work
The Internet or the Net
A collection of computers and other devices connected together via communicationsModemsCablesTelephone linesSatellites
A worldwide collection of networks that links millions of businesses, government agencies, educational institutions, and individuals
message board
instant messaging
file transfer
Web
The Services on the Internet
chat
History of the InternetAPRANET
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
ARPANETA 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 forthe 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 connectionConnect to service provider through a high-speed connection line leased from local telephone company
Dial-up accessComputer, modem, regular telephone lineDial into an ISP
Newer high-speed technologies
DSLCable modem
Backbone• Inner structure
of the Internet• Communications
lines that carry the heaviest amount of traffic
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
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
Internet Corporation for Assigned Names and Numbers (ICANN)
Group that assigns and controls TLDs
What systems control domain names?
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
address text box
What are the parts of a URL?
protocol domain name path
Click to view Web Linkthen click URLs
http://www.nationalgeographic.com/travel/index.html
p. 2.13 Fig. 2-10
Next
filename
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
maps
stock quotes
reference tools
sports and weather
search engine
What services are often found on a portal?
local , national, and
worldwide news
free personal
Web pages
instant messaging
calendars
shopping malls and auctions
newsgroups or message
boards
chat rooms
A Graphic on the WebA digital representation of information such as a drawing, chart, or photograph
What is audio? What is MP3?
Music, speech, or any other sound
A popular technology that compresses audio
Reduces an audio file to about one-tenth of its original size
Streaming audio
enables you to listen to the sound as it downloads
What is video?
Consists of full-motion images that are played back at various speeds
Most video also has accompanying audio
MPEG standard:Video files that you must download completely before you can play them on the computer
Streaming video: allows you to view live video images as they download RealVideo 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 ofe-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
Upload, or copy, the site to the
Web server
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
How do you deploy a Web site?
What is e-mail?
The transmission of messages and files via a computer network
Use an e-mail program to work with messages
create
receive
store print
sendforward
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
Top Related