Chapter 9: The Internet and World Wide Web. Succeeding with Technology, Third Edition 2 Objectives Describe how the Internet developed and how hardware,

Chapter 9:The Internet and World Wide Web

Succeeding with Technology, Third Edition 2

Objectives• Describe how the Internet developed and how

hardware, protocols, and software work together to create the Internet

• Explain the underlying structure of the Web and the technologies that support it

• Define the categories of information and services that the Internet and Web provide and the forms of communication they support

• Explain what Internet2 is and the types of applications it will provide in the future

Succeeding with Technology, Third Edition 3

A Brief History of the Internet• Internet

– Global, public network of computer networks

• Computer network– Collection of computing devices connected together

to share resources such as files, software, processors, storage, and printers

• Internetwork– Users on different networks can communicate and

share data

Succeeding with Technology, Third Edition

A Brief History of the Internet• Internet hosts

– Computers joined into the network

• 1957– Computing was done primarily on large mainframe computers

• 1969– ARPA commissioned ARPANET for research into networking

• About 17% of the world population uses the Internet– Digital divide

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A Brief History of the Internet

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Internet Hardware• Protocols

– Rules implemented in network software and hardware– Establish connections between two or more computers,

allowing them to communicate

• Internet backbone– The main Internet pathways and connections

• Network service providers– The large telecom companies that provide the hardware over

which the Internet travels

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Internet Hardware• Points of presence (POPs)

– Utility stations which enable customers to connect to the Internet

• Internet service providers (ISP)– Companies that provide customers access to the Internet

through network service providers’ (NSPs’) points of presence (POPs)

• Routers– Devices —typically a small to large unit with network ports—

which manage network traffic by finding the fastest route for messages to travel to their destination

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Internet Hardware

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Internet Hardware

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Assessing the Internet• Dial-up connection

– Low-speed Internet service

• Cable modem connection– High-speed Internet service– transfer rates as high as 8 Mbps, provided by cable television service

providers

• DSL (digital subscriber line) connection – Uses customer’s phone line– Users can use Internet and talk on the phone simultaneously

• Digital satellite service (DSS)• Broadband over power lines (BOP)

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Assessing the Internet

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Internet Protocols• Protocols for the Internet

– Transmission Control Protocol (TCP): enables two hosts to establish a connection and exchange streams of data

– Internet Protocol (IP): The formatting and addressing scheme for Internet data packets

• IP address: identifier for Internet hosts – Four numbers (0 to 255) (or 32 bits) separated by periods, such as 64.233.161.104– Dynamic/static

• Internet– A packet switching network

• Domain names– Associated English names assigned to IP addresses– Domain Name System (DNS)

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Internet Software• Client/server: A relationship between two computer programs in

which one program makes a service request from another – Client makes a service request

– Server provides the service

• Port– Logical addresses used by clients and servers that is associated with a

specific service

• Peer-to-peer (P2P) networking– Does not utilize a central server

– Facilitate communications directly between clients

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Internet Software

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Web Basics• Hyperlink

– Element in an electronic document —a word, phrase, or image—that when clicked, opens a related document

– Hypertext, hypermedia

• Hypertext Transfer Protocol (HTTP) – Protocol controls communication between Web clients and servers

• Web browser: web client such as Internet Explorer, Netscape, and Firefox– Software used to request Web pages from Web servers

• Web server– Stores and delivers Web pages and other Web resources such as

interactive Web content

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Web Basics• Uniform Resource Locator (URL)

– Acts as a Web page address– Incorporates domain name of Web server and

location of Web page file on server

• Top-level domain (TLD)– Final portion of domain name - .com, .edu

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Web Basics

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Web Markup Languages• Hypertext Markup Language (HTML)

– Used to specify the formatting of a Web page

• HTML tag

– Command that tells a Web browser how to display items on a page

– Used by browser to describe the formatting of a page

• XML

– Provides method for describing and classifying the content of data in a Web page

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Web Markup Languages• Semantic Web

– Extension of current Web– Provides common framework that supports

• Sharing and reuse of data across application, enterprise, and community boundaries

• Publishers are able to use XML to separate data from Web page formatting

• XHTML– Embodies the best of both HTML and XML

• Cascading Style Sheets– Provide consistent design across multiple pages of a site

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Web Markup Languages

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Programming the Web• Cookies

– Small text files stored on your computer – Can contain data or unique identifier that can be

used to look up your personal profile in a database – May be a threat to security and privacy

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Web Browser Plug-Ins• Plug-in

– Works with a Web browser to offer extended services

• Flash – Popular plug-in– Enables users to view animations and videos, and

interact with games and other multimedia content

• Content streaming– Media begins playing while the file is being delivered

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Internet and Web Applications• Classification of Web sites

– Search engines, subject directories, and portals– Communication and collaboration – News – Education and training– E-commerce– Travel– Employment and careers– Multimedia and entertainment– Information

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Search Engines, Subject Directories,and Portals• Search engine

– Tool that makes it easier to find related documents from diverse Internet sources by specifying words that are key to a topic of interest (keywords)

• Search engines scour the Web with bots (automated programs) called spiders– Crawling

• Mashup– A single application that combines different Web

applications24


Search Engines, Subject Directories,and Portals

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Communication and Collaboration• Pervasive communications

– Ability to communicate with anyone through a variety of formats from anywhere at anytime

• Synchronous communication– People communicate in real time exchanging

thoughts in a flowing conversation

• Asynchronous communication – Allows participants to leave messages for each other

to be read, heard, or watched, and responded to at the recipient’s convenience

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Communication and Collaboration• Text communications

– Available in both synchronous and asynchronous formats

– Emoticons (smiley faces)• Combine keyboard characters to create a sideways facial

expression

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Communication and Collaboration• E-mail

– Transmission of messages over network to support asynchronous text-based communication

• Header• Body• E-mail attachment

– Typically an image file, Word document, music file, or spreadsheet that travels with the message but is not part of the ASCII text message itself

• E-mail cannot contain binary data – data that is encoded for a processor to process

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Communication and Collaboration• Listservs

– Special-interest groups that create online communities for discussing topics via e-mail

• Newsletter– Subscription-based e-mail service

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Communication and Collaboration

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Instant Messaging and Chat• Synchronous one-to-one text-based communication

over the Internet• Instant messaging software supports the following

services– Instant messages– Chat– Nudges, animated winks, and graphics– Web links– Image, sounds– Files and file sharing– Talk– Streaming content

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Instant Messaging and Chat• Chat

– Synchronous text messaging between two or more users

• Channels or chat rooms– Topic-related forums

• Virtual chat– Provides a virtual world for you to enter for chat and

interaction with others• Avatar

– A 3D representation of yourself in the virtual world

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Instant Messaging and Chat

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Web 2.0 and Social Networking• Web 2.0

– Web resources that allow average users to collaborate and contribute to Web content with shared data and document access

• Social networking sites• Media-sharing sites• Wikis• Social bookmarking sites

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Web 2.0 and Social Networking• Social Networking

– Web-based tools that allow users to share information about themselves and find, meet, and converse with others

• Facebook, Twitter

• Wiki– Web site designed to allow users to add, remove, edit

content

• Media-sharing sites allow users to store and share digital media files– YouTube, Flickr

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Web 2.0 and Social Networking

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Education and Training• Educational institutions of all types and sizes use the

Web to enhance classroom education

– Parental control/content-filtering software helps make browsing safe for children

• Educational support products (Blackboard and WebCT)

– Provide an integrated Web environment

• Distance education

– Conducting classes over the Web with no physical class meetings

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Education and Training

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E-commerce

• The Web provides a convenient platform for marketing and selling products and is very helpful in collecting marketing data

• The Web strengthens communications with customers and improves overall customer satisfaction

• Doing business electronically over the Web and private networks is known as e-commerce

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Travel• The Web

– Has had a profound effect on the way we plan and prepare for trips

• Mapquest – Assists travelers in finding their way around town and

between towns

• Travel Web sites

– Assist travelers in finding the best deals on flights, hotels, car rentals, vacation packages, and cruises

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Employment and Careers• Consider the Web’s role in the following job-

hunting strategy

– Select a career

– Discover who the players are in your chosen career

– Learn about the companies that interest you

– Network with others in the field

– View job listings at general employment Web sites

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Multimedia and Entertainment• Music• Internet radio• Digitally delivered to your computer over the

Internet• File sharing and online music services• Compressed music formats• MP3• Television and movie industry

– Making the move to Internet distribution

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Multimedia and Entertainment• Genre of multiplayer online games

– Action– Board– Card– Flight Simulation– Multiuser dimension or multiuser dungeon– Role-playing games– Sims– Sports– Strategy– Trivia/puzzle

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Multimedia and Entertainment

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Information• Curiosity-driven research

– Looking up information at the moment a thought or question strikes us

– Responsible for most of the world’s great inventions

• Assigned research– You are given a topic to explore for the purpose of

education

• Selecting and Refining a Research Topic– Generally done through many stages of refinement

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Information• Sources of information• College-level research typically requires that

sources are cited• Plagiarism• Using information or quotes from another source

without citing that source• Electronic sources of information• In Web research, you must follow up and check

information for validity and impartiality 46


Information

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Summary• Internet

– The largest publicly owned network of networks

– Combines hardware, protocols, and software to serve its users• Client/server technology provides a medium for users to

publish, view, and find information• Web plug-ins

– Work with Web browsers to offer extended services• Portals

– Web pages that provide an entry point to the Web• Web authoring software

– Allows you to create HTML documents without having to know the HTML language

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Summary• The Web provides a wide range of helpful

applications• Synchronous and asynchronous communication

– Text, voice, and video based

• The Web provides information from local to international news to online library catalogues, databases, and public opinion

• Internet2 is a research and development group working to develop advanced applications for tomorrow’s Internet

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Documents

Chapter 9: The Internet and World Wide Web. Succeeding with Technology, Third Edition 2 Objectives Describe how the Internet developed and how hardware,