The Internet and the World Wide Web

1. The Internet and the World Wide Web Chapter 7 – Computers: Understanding Technology William M. Pegram

2. Chapter Outline • Uses of the Internet • Connecting to the Internet • Internet Addresses • Packet transmission • New applications William M. Pegram

3. Uses of the Internet • Communications • Entertainment • E-Commerce • Research/Knowledge Acquisition & Web Publishing • Distance Learning William M. Pegram

4. 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 William M. Pegram

5. 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 William M. Pegram

6. 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 William M. Pegram

7. 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 William M. Pegram

8. 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) William M. Pegram

9. 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 William M. Pegram

10. Research/Knowledge Acquisition • Search engines • Increase in plagiarism and plagiarism-detection tools (e.g. www.turnitin.com) • Wikipedia – online, collaborative encyclopedia William M. Pegram

11. 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 William M. Pegram

12. Connecting to the Internet • Types of Internet Connections • Dial-up • Cable • DSL • Wireless • Satellite William M. Pegram

13. 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 William M. Pegram

14. 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) William M. Pegram

15. 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 William M. Pegram

16. 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 William M. Pegram

17. Newer Internet Applications • Peer-to-peer (P2P) file sharing - BitTorrent • Internet telephone service (Voice over IP) William M. Pegram