Transcript Principles of Information Systems Eighth Edition

Principles of Information
Systems
Chapter 7
The Internet, Intranets, and Extranets
Why Learn About the Internet?
• Internet is an important part of most people’s lives
– Individuals can investigate career opportunities
– Businesses sell and advertise online
– Employees can communicate with coworkers and
bosses
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Use and Functioning of the Internet
• Internet: ?
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Use and Functioning of the Internet
• Internet: a collection of interconnected networks,
all freely exchanging information
• ARPANET
– Ancestor of the Internet
– Project started by the U.S. Department of Defense
(DoD) in 1969
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Use and Functioning of the Internet
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Use and Functioning of the Internet
(continued)
• Internet Protocol (IP): communication standard
that enables traffic to be routed from one network
to another as needed
• Research to make Internet faster and easier to use
– “Digital objects”: allow all types of computer systems
to use and share programs and data
– Internet2 (I2), Next Generation Internet (NGI),
Abilene: provide Internet speeds of up to 2 Gbps or
more
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Use and Functioning of the Internet
(continued)
Table 7.1: A Brief History of the Internet
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How the Internet Works
• Internet transmits data from one computer (called a
host) to another
• If the receiving computer is on a network to which
the first computer is directly connected, it can send
the message directly
• If the receiving computer is not on a network to
which the sending computer is connected, the
sending computer relays the message to another
computer that can forward it
• Data is passed in chunks called packets
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How the Internet Works (continued)
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How the Internet Works (continued)
• Transmission Control Protocol (TCP): widely
used transport layer protocol that is used in
combination with IP by most Internet applications
• Uniform Resource Locator (URL): assigned
address on the Internet for each computer
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How the Internet Works (continued)
• Domain name and IP address - ?
• ICANN –Internet Corporation for Assigned Names
and Numbers
Table 7.2: U.S. Top-Level Domain Affiliations
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How the Internet Works (continued)
• Accessing the Internet
– Connect via LAN server
– Connect via Serial Line Internet Protocol
(SLIP)/Point-to-Point Protocol (PPP)
– Connect via an online service: America Online and
Microsoft Network
– Other ways to connect cell phones, PDAs, and home
appliances: e.g., wireless application protocol (WAP)
for cell phones
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How the Internet Works (continued)
Figure 7.1: Routing Messages over the Internet
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How the Internet Works (continued)
Figure 7.2: Internet Growth: Number of Internet Domain Names
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How the Internet Works (continued)
Figure 7.3: Several Ways to Access the Internet
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Internet Service Providers
• Internet service provider (ISP): any company that
provides individuals or organizations with access to
the Internet
• Most charge a monthly fee
• Many ISPs and online services offer broadband
Internet access through digital subscriber lines
(DSLs), cable, or satellite transmission
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Internet Service Providers (continued)
Table 7.3: A Representative List of Internet Service Providers
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Internet Service Providers (continued)
Table 7.4: Approximate Times to Perform Basic Tasks with Various
Internet Connections
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The World Wide Web
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The World Wide Web
• Also called the Web, WWW, or W3
• Menu-based system that uses the client/server
model
• Organizes Internet resources throughout the world
into a series of menu pages, or screens, that
appear on your computer
• Hypermedia: tools that connect the data on Web
pages, allowing users to access topics in whatever
order they wish
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The World Wide Web
• The World Wide Web was
developed by Tim Berners-Lee
at CERN, The European
Organization for Neuclear
Research in Geneva
[Center Europeane pour la
Recherche Nucleaire]
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The World Wide Web (continued)
• Hypertext Markup Language (HTML): standard
page description language for Web pages
• HTML tags: let the browser know how to format
text on a Web page and whether images, sound,
and other elements should be inserted
• Extensible Markup Language (XML): markup
language for Web documents containing structured
information, including words, pictures, and other
elements
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The World Wide Web (continued)
Figure 7.4: Sample Hypertext Markup Language
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The World Wide Web (continued)
Web
Documents
index.html
HTML
Documents/
Linked Files
http://www.buu.ac.th/index.html
REQUEST
HTTP
The Internet
HTTP
HTTPD
Client
Web Browser
Web Page
Home Page
HTML
Document
index.html
Web Server
Web Site
Web Browsers
• Web browser: software that creates a unique,
hypermedia-based menu on a computer screen,
providing a graphical interface to the Web
– Menu consists of graphics, titles, and text with
hypertext links
– Popular Web browsers: Microsoft Internet Explorer,
Netscape Navigator, Mozilla Firefox, Apple
Computer’s Safari
• Applet: small program embedded in Web pages
• Web browser plug-in: external program that is
executed by a Web browser when it is needed
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Search Engines and Web Research
• Search engine: Web search tool
– Examples: Yahoo.com, Google.com
• Most search engines are free
• Searches can use words, such as AND and OR to
refine the search
• Meta-search engine: submits keywords to several
individual search engines and returns results from
all these search engines
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Search Engines and Web Research
(continued)
Table 7.6 Popular Search Engines
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Web Programming Languages
• Java
– Object-oriented programming language from Sun
Microsystems based on C++
– Allows small programs (applets) to be embedded
within an HTML document
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Web Programming Languages
(continued)
Figure 7.6: Downloading an Applet from a Web Server
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Web Programming Languages
(continued)
• Other programming languages used to develop
Web sites
–
–
–
–
JavaScript
VBScript
ActiveX
Hypertext Preprocessor (PHP)
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Developing Web Content
•
Suggestions for creating a Web page
1. Computer must be linked to a Web server
2. Web browser program needed to view the HTML
pages you create
3. Options for designing the Web page
a) Write your copy with a word processor, and use an
HTML converter to convert the page into HTML format
b) Use an HTML editor to write text and add HTML tags
c) Edit an existing HTML template to meet your needs
d) Use an ordinary text editor and type the start and end
tags for each item
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Developing Web Content (continued)
•
Suggestions for creating a Web page (continued):
1. See HTML page in browser; correct any mistakes
2. Add links to your home page
3. Store pictures as files before adding them
a) Draw them using a graphics software package
b) Copy pictures from other Web pages (with
permission)
c) Buy a disk of clip art
d) Scan photos
e) Use a digital camera
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Developing Web Content (continued)
•
Suggestions for creating a Web page (continued):
1. Add sound by using a microphone connected to
your computer to create a file, and then adding a
link to the file on a Web page
2. Upload the HTML file to your Web site
3. Review the Web page to make sure that all links
are correctly established to other Web sites
4. Advertise your Web page to others and encourage
them to take a look and send feedback by e-mail
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Web Services
• Web services: standards and tools that streamline
and simplify communication among Web sites for
business and personal purposes
• XML is used within a Web page to describe and
transfer data between Web service applications
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Web Services (continued)
• Other components used in Web service
applications:
– SOAP (Simple Object Access Protocol)
– WSDL (Web Services Description Language)
– UDDI (Universal Discovery Description and
Integration)
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Internet and Web Applications
• The types of Internet and Web applications
available are vast and ever expanding
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Business Uses of the Web
• In 1991, Commercial Internet Exchange (CIX)
Association was established to allow businesses to
connect to the Internet
• Firms use the Internet for many types of
applications
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E-Mail, Instant Messaging, and Push
Technology
• E-mail
– No longer limited to simple text messages
– Can embed sound and images
– Can attach files
• Instant messaging: online, real-time
communication between two or more people who
are connected to the Internet
• Push technology: automatic transmission of
information over the Internet rather than make
users search for it with their browsers
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E-Mail, Instant Messaging, and Push
Technology (continued)
Table 7.7: Some Common Abbreviations Used in Personal E-Mail
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Internet Cell Phones and Handheld
Computers
• Cell phones connected to the Internet allow people
to search for information, buy products, and chat
with business associates and friends
• Short Message Service (SMS) or texting
– Brief text messages can be sent between two or
more cell phone users
• Handheld computers and other devices are
connected to the Internet using phone lines or
wireless connections
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Career Information and Job Searching
• Use search engines to look for specific companies
or industries
• Internet sites specialize in helping you find job
information and apply for jobs online
– Examples: www.monster.com, www.hotjobs.com,
and www.careerbuilder.com
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Telnet and FTP
• Telnet: terminal emulation protocol that enables
users to log on to other computers on the Internet
to gain access to public files
• File Transfer Protocol (FTP): protocol that
describes a file transfer process between a host
and a remote computer and allows users to copy
files from one computer to another
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SSH Secure Shell File Transfer
Upload
Download
Web Log (Blog), Video Log (Vlog), and
Podcasting
• Web log or blog: Web site that people create and
use to write about their observations, experiences,
and feelings on a wide range of topics
• Video log or vlog: video content placed on the
Internet using the same overall approach as a blog
• Podcast: audio broadcast over the Internet
– People and corporations use podcasts to listen to
audio material, increase revenues, or advertise
products and services
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Usenet and Newsgroups
• Usenet: system closely allied with the Internet that
uses e-mail to provide a centralized news service
– Protocol that describes how groups of messages
can be stored on and sent between computers
• Newsgroups: online discussion groups that focus
on specific topics
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Usenet and Newsgroups (continued)
Table 7.8: Selected Usenet Newsgroups
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Chat Rooms
• Chat room: enables two or more people to engage
in interactive “conversations” over the Internet
• Internet Relay Chat (IRC) requires participants to
type their conversation rather than speak
• Voice chat allows participants to speak their
conversation
– Must have a microphone, sound card, speakers, a
fast modem or broadband, and voice-chat software
compatible with the other participants’
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Internet Phone and Videoconferencing
Services
• Internet phone service
– Relatively inexpensive, especially for international
calls
• Voice-over-IP (VoIP) technology
– Network managers can route phone calls and fax
transmissions over the same network they use for
data
• Internet videoconferencing
– Supports both voice and visual communications
– Webcasts or Webinars
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Content Streaming
• Method for transferring multimedia files, radio
broadcasts, and other content over the Internet
• Data stream of voice and pictures plays more or
less continuously without a break, or with very few
breaks
• Enables users to browse large files in real time
• Works best when the transmission of a file can
keep up with the playback of the file
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Shopping on the Web
• You can shop for almost anything over the Internet
• Convenient, easy, and cost effective
• Many Web sites also offer free shipping and pickup
for returned items
• Bot: a software tool that searches the Web for
information, products, or prices
– Finds the best prices or features from multiple Web
sites
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Web Auctions
• Web auction: Internet site that matches buyers
and sellers
– Businesses grow or reach customers for a low cost
per transaction
• One of the most popular auction sites: eBay
• Potential problems with auction Web sites
– Auction sites cannot always determine whether the
people and companies listing products and services
are legitimate
– Some Web sites have illegal or questionable items
offered
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Music, Radio, Video, and TV on the
Internet
• Audio and video programs: play on the Internet or
download files for later use
• Music players and music formats such as MP3:
download music from the Internet and listen to it
anywhere
– Musicians can gain exposure without a lucrative
music contract
• Radio broadcasts
• Audio books
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Music, Radio, Video, and TV on the
Internet (continued)
• Video and TV are increasingly becoming available
on the Internet
• New, innovative devices let you record TV
programs and view them at any time and place
• Many content providers offer their programs over
the Internet
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Office on the Web
• Internet office: Web site that contains files, phone
numbers, e-mail addresses, an appointment
calendar, and more
– Allows your desktop computer, phone books,
appointment schedulers, and other important
information to be with you wherever you are
• Many services and software products give you
remote access to your files and programs over the
Internet
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Internet Sites in Three Dimensions
• Some Web sites offer three-dimensional views of
places and products
• Examples
– 3-D Internet auto showroom: allows people to get
different views of a car
– 3-D real estate site: people can tour the property, go
into different rooms, etc.
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Other Internet Services and
Applications
• Libraries: provide vast amounts of information
• Movies: ordered and delivered over the Internet
• Critical information during times of disaster or
terrorism
• Translation: words, sentences, or complete
documents from one language into another
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Other Internet Services and
Applications (continued)
• Distance learning: online courses
• Internet cameras: conduct job interviews; hold
group meetings with people around the world;
monitor young children at daycare centers, etc.
• Connect with friends or others with similar interests
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Intranets and Extranets
• Intranet: internal corporate network built using
Internet and World Wide Web standards and
products
– Used by employees to gain access to corporate
information
– Reduces the need for paper
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Intranets and Extranets (continued)
• Extranet: network based on Web technologies that
links selected resources of a company’s intranet
with its customers, suppliers, or other business
partners
• Virtual private network (VPN): secure connection
between two points across the Internet
• Tunneling: process by which VPNs transfer
information by encapsulating traffic in IP packets
over the Internet
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Intranets and Extranets (continued)
Table 7.9: Summary of Internet, Intranet, and Extranet Users
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Net Issues
• Management issues
– Preventing attacks
• Service and speed issues
– Keeping up with Internet traffic and traffic on
company intranets
•
•
•
•
Privacy
Fraud
Security
Unauthorized Internet sites
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Summary
• Internet: collection of interconnected networks, all
freely exchanging information
• Internet Protocol (IP): communication standard that
enables traffic to be routed from one network to
another as needed
• Packets: Internet data passed in chunks
• Transmission Control Protocol (TCP): widely used
transport layer protocol that is used in combination
with IP by most Internet applications
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Summary (continued)
• Uniform Resource Locator (URL): assigned address
on the Internet for each computer
• World Wide Web: menu-based system that
organizes Internet resources into a series of menu
pages, or screens, that appear on your computer
• Hypertext Markup Language (HTML): standard page
description language for Web pages
• Search engine: Web search tool
• Internet and Web applications: e-mail, instant
messaging, Internet cell phones, Web logs,
newsgroups, Web shopping, etc.
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Summary (continued)
• Intranet: internal corporate network built using
Internet and World Wide Web standards
• Extranet: network based on Web technologies that
links selected resources of a company’s intranet
with its customers, suppliers, or other business
partners
• Network issues: management, service, speed,
privacy, fraud, security, and unauthorized Internet
sites
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Principles and Learning Objectives
• The Internet is like many other technologies—it
provides a wide range of services, some of which
are effective and practical for use today, others that
are still evolving, and still others that will fade away
from lack of use
– Briefly describe how the Internet works, including
alternatives for connecting to it and the role of
Internet service providers
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Principles and Learning Objectives
(continued)
• Originally developed as a document-management
system, the World Wide Web is a menu-based
system that is easy to use for personal and
business applications
– Describe the World Wide Web and the way it works
– Explain the use of Web browsers, search engines,
and other Web tools
– Identify and briefly describe the applications
associated with the Internet and the Web
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Principles and Learning Objectives
(continued)
• Because the Internet and the World Wide Web are
becoming more universally used and accepted for
business use, management, service and speed,
privacy, and security issues must continually be
addressed and resolved
– Identify who is using the Web to conduct business
and discuss some of the pros and cons of Web
shopping
– Outline a process for creating Web content
– Describe Java and discuss its potential impact on
the software world
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Principles and Learning Objectives
(continued)
– Define the terms intranet and extranet and discuss
how organizations are using them
– Identify several issues associated with the use of
networks
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Review question #7
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