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The Internet and the World Wide Web

Chapter 7 – Computers: Understanding Technology

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Chapter Outline

• Uses of the Internet

• Connecting to the Internet

• Internet Addresses

• Packet transmission

• New applications

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Uses of the Internet

• Communications

• Entertainment

• E-Commerce

• Research/Knowledge Acquisition & Web Publishing

• Distance Learning

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Communications

• Email (electronic mail) – The most widely used Internet application– Usefulness of email threatened by spamming, phishing, and

worms• Perhaps 80% of email messages are spam (bulk unsolicited email)• Phishing is email that purports to be from someone but is from

someone else and attempts to have the recipient reveal confidential information

• Worms are self-replicating programs and are used to get a computer to send spam

– An internet service provider (ISP) is an organization that provides consumer access to the internet, usually charging a subscription fee, and ISP’s provide a unique email address to their clients, e.g. wmpegram@comcast.net where Comcast is the ISP

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Communications (cont.)

• E-mail (cont.)– Most employers will provide a unique email address to their

employees (e.g. wpegram@nvcc.edu)– Email addresses are also available for free from other sources –

e.g. Yahoo, Hotmail, Gmail, MSN• Such email addresses can be permanent whereas those provided

by ISP or employer typically end when one stops paying subscription to ISP or no longer works for the employer

– Most email providers permit one to access email through specialized email client programs, such as Outlook, Eudora, Outlook Express (succeeded by Windows Mail) and through a browser

• Student VCCS email can only be accessed through a browser

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Communications (cont.)• Chat rooms – real-time (live) discussions• Instant messaging (IM) – like chat, but only two participants. Popular

programs: – AOL Instant Messenger and ICQ– Yahoo! Messenger– Windows Live Messenger – previously MSN Messenger– IRC (Internet Relay Chat)

• Previously IM use has been social, but increasingly used in corporate world

• Mailing Lists – email sent to an address goes to everyone on the list– Moderated – emails have to be approved by administrator to go to

everybody vs. unmoderated (no approval step)– One can opt to receive every email or digests of emails sent over a

particular time period

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Communications (cont.)

• Web Sites for Communication– Blogs (originally called weblogs) – frequently updated journals

posted on a web site – blogger.com provides blog creation for free

– Electronic discussion groups/bulletin boards • Moderated/unmoderated distinction here as well

– Social networking sites – building online social networks• Use a variety of techniques – chat, email, discussion groups,

blogging, etc.• Users create a profile of themselves and can be friends with other

users• MySpace and Facebook are the most popular

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Entertainment

• Online Games – single and multiplayer

• Online Gambling

• Online Music and Video – mp3 is the most common format for sound– Music download services - iTunes– Increase in online video is one of the biggest

recent changes in the Internet – sites where anyone can upload (youtube.com), TV network sites (watch TV shows)

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Electronic Commerce

• Business to Consumer – Apparel is biggest category, followed by books, music, video, auction items, toys, and computer hardware

• Business to business (B2B) – advertise products, order raw materials, recruit employees, file government forms and reports

• Advertising– Banner ads and popup windows– Targeted advertising – ads accompanying Google

search engine results will be a function of the search keywords

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Research/Knowledge Acquisition

• Search engines

• Increase in plagiarism and plagiarism-detection tools (e.g. www.turnitin.com)

• Wikipedia – online, collaborative encyclopedia

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Distance Learning

• WebCT and Blackboard are the two most popular platforms for college online courses; WebCT acquired by Blackboard in February 2006 and will be phased out as independent brand

• Both NVCC and GMU are increasing their use of distance learning

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Connecting to the Internet

• Types of Internet Connections– Dial-up– Cable– DSL– Wireless– Satellite

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Internet Addresses

• Internet Protocol (IP) Addresses – 4 numbers ranging from 0 to 255 separated by periods, e.g. 207.171.181.16

• Each computer (network) connected to the internet has a unique IP address

• Type ipconfig at Command Prompt to determine IP address

• Some ISPs dynamically allocate IP addresses so they can change over time

• Uniform Resource Locator (URL) – e.g. http://www.amazon.com – protocol then format then domain name then domain suffix then any path within

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Original Set of Domain Suffixes

• .com• .edu• .gov• .mil• .net• .org• 2-digit country codes, e.g. .us (.us used by state

and local governments, e.g. NVCC used to be nv.cc.va.us)

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New Domain Suffixes• .aero - airline• .biz• .cat – Catalan language and culture• .coop – business cooperatives• .info• .int• .jobs• .mobi• .museum - museums• .name• .pro - professionals• .tel• .travel

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Packets

• Files sent over the internet are generally broken into smaller pieces, called packets. These packets are then reassembled at the other end

• The path a packet takes depends on availability – this is called packet-switching or dynamic routing

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Newer Internet Applications

• Peer-to-peer (P2P) file sharing - BitTorrent

• Internet telephone service (Voice over IP)