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

Principles of Information Systems

Eighth Edition

Chapter 7

The Internet, Intranets, and Extranets

2Principles of Information Systems, Eighth Edition

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


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


How the Internet Works (continued)

• Data is passed in chunks called packets

• 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



• Accessing the Internet– Connect via LAN server– Connect via Serial Line Internet Protocol

(SLIP)/Point-to-Point Protocol (PPP)– Connect via an online service– 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



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



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

• 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 (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


The World Wide Web (continued)

Figure 7.4: Sample Hypertext Markup Language


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)


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


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


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


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


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.


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

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

Documents

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