principles of information systems chapter 7 the internet, intranets, and extranets

Principles of Information Systems

Chapter 7

The Internet, Intranets, and Extranets

3Principles of Information Systems, Eighth Edition

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


Use and Functioning of the Internet

• 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


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


Use and Functioning of the Internet (continued)

Table 7.1: A Brief History of the Internet


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


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



Table 7.2: U.S. Top-Level Domain Affiliations

• Domain name and IP address - ?• ICANN –Internet Corporation for Assigned Names

and Numbers



• 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



Figure 7.1: Routing Messages over the Internet



Figure 7.2: Internet Growth: Number of Internet Domain Names



Figure 7.3: Several Ways to Access the Internet


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


Internet Service Providers (continued)

Table 7.3: A Representative List of Internet Service Providers


Internet Service Providers (continued)

Table 7.4: Approximate Times to Perform Basic Tasks with Various Internet Connections


The World Wide Web


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


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]


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



Figure 7.4: Sample Hypertext Markup Language

The Internet

Client Web Browser

HTTPDWeb Server

Web SiteHTML

Documentindex.html

HTML Documents/Linked Files

REQUEST

Web PageHome Page

http://www.buu.ac.th/index.html

HTTP

HTTP

Web Documentsindex.html



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


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


Search Engines and Web Research (continued)

Table 7.6 Popular Search Engines


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


Web Programming Languages (continued)

Figure 7.6: Downloading an Applet from a Web Server


Web Programming Languages (continued)

• Other programming languages used to develop Web sites– JavaScript– VBScript– ActiveX– Hypertext Preprocessor (PHP)


Developing Web Content

• Suggestions for creating a Web page1. 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 pagea) 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


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 thema) 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


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


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


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)


Internet and Web Applications

• The types of Internet and Web applications available are vast and ever expanding


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


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


E-Mail, Instant Messaging, and Push Technology (continued)

Table 7.7: Some Common Abbreviations Used in Personal E-Mail


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


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


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

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


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


Usenet and Newsgroups (continued)

Table 7.8: Selected Usenet Newsgroups


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’


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


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


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


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


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


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


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


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.


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


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


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


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


Intranets and Extranets (continued)

Table 7.9: Summary of Internet, Intranet, and Extranet Users


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


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


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.


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


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


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



• 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



– Define the terms intranet and extranet and discuss how organizations are using them

– Identify several issues associated with the use of networks

Review question #7

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