1. THE INTERNET & THE WORLD WIDE WEB Exploring Cyberspace5
Chapter

2. Chapter Topics 2.1 Connecting to the Internet
2.2 How Does the Internet Work?
2.3 The World Wide Web
2.4 The Online Gold Mine
2.5 The Intrusive Internet

3. 2.1 Connecting to the Internet

4. Internet history To connect you need
Began with 1969s ARPANET for U.S. Dept. of Defense
62 computers in 1974
500 computers in 1983
28,000 computers in 1987
Early 1990s, multimedia became available on Internet
2010 = about 2 billion people on Internet
To connect you need
1. An access device (computer with modem)
2. A means of connection (phone line, cable hookup, or
wireless)
3. An Internet access provider

5. DEFINITION: Bandwidth is an expression of how much data – text, voice, video, and so on – can be sent through a communication channel in a given amount of time. DEFINITION: Baseband is a slow type of connection that allows only one signal to be transmitted at a time. DEFINITION: Broadband is a high-speed connection that allows several signals to be transmitted at once.

6. Data Transmission Speeds
Originally measured in bits per second (bps)
8 bits are needed to send one character, such as
A or a
Kbps connections send 1 thousand bits per second
Mbps connections send 1 million bits per second
Gbps connections send 1 billion bits per second
Uploading & Downloading
Upload—transmit data from local to remote computer
Download—transmit data from remote to local computer

7. High-Speed Phone Lines
DSL line
Uses regular phone lines, DSL modem
Receives data at 1.5 ̶ 10 Mbps; sends at 128 Kbps – 1.5 Mbps
T1 line—very expensive
Traditional trunk line; carries 24 normal telephone circuits
Transmission rate of 1.5 ̶ 6 Mbps (T3 = 6 – 45 Mbps)
Cable modem
Receives data at up to 30 Mbps; sends at about 1.4 Mbps

8. Satellite Wireless Transmits data between satellite dish
and satellite orbiting earth
Sends data at around 200 ̶ 512 Kbps;
receives at 1 ̶ 5 Mbps
Connection is always on
User needs to buy or lease satellite dish and
modem and have them connected

9. Other Wireless Wi-Fi & 3G/4G Wi-Fi—stands for “wireless fidelity”
Transmits data wirelessly up to 54 Mbps for 300 – 500 feet from access point (hotspot)
Typically used with laptops and tablets that have Wi-Fi hardware
3G—stands for “third generation”; 4G = “fourth generation”
High-speed wireless that does not need access points, because it uses existing cellphone system
Used mostly in smartphones

10. Internet Access Providers
Two Types
1. Internet Service Provider (ISP) — e.g., Earthlink and Comcast
Company that links online users to its servers, which link users to the Internet through another company’s network
2. Wireless Internet Service Provider (WISP) — e.g., AT&T, Cingular, Verizon
Enables wireless-equipped laptop/tablet and smartphone users to access Internet

11. 2.2 How Does the Internet Work?

12. The Internet consists of hundreds of thousands of smaller networks
Protocols
The set of rules a computer follows to electronically transmit data.
TCP/IP (Transmission Control Protocol/Internet Protocol) is the Internet protocol
Developed in 1978 by ARPA; used for all Internet transactions
Packets
Fixed-length blocks of data for transmission
Data transmissions are broken up into packets and re-assembled at destination (the IP—Internet Protocol— address)

13. IP Addresses Every device connected to the Internet has an address
Each IP address uniquely identifies that device
The address is four sets of numbers separated by periods (e.g., )
Each number is between 0 and 255

14. 2.3 The World Wide Web

15. Browsers, Websites, & Web Pages
The web and the Internet are not the same; the web is multimedia-based, and the Internet is not. The Internet is the infrastructure that supports the web.
Browsers
Software for web surfing (for accessing particular servers on the Internet); examples = Internet Explorer
Mozilla FireFox
Apple Macintosh’s Safari
Google’s Chrome

16. Website
The location on a particular computer (server) that has a unique address; example =
The website (server) could be anywhere — not necessarily at company headquarters
Web Page
A document on the web that can include text, pictures, sound, and video
The first page on a website is the Home page
The Home page contains links to other pages on the website (and often other websites)

17. TCP/IP— As explained, general Internet Protocol
HTTP—Protocol Used to Access World Wide Web
Hypertext Markup Language (HTML)
The “markup” language used in writing
and publishing web pages
Set of instructions used to specify
document structure, formatting,
and links to other documents on the web
Hypertext links connect one web document to another

18. Web browsers interpret HTML and allow you to move around the Internet and the web
Come preinstalled on most PCs, but you can download others

19. Search Services & Search Engines
Organizations that maintain databases accessible through websites to help you find information on the internet
Examples: portals like Yahoo! and Bing, plus Google, Ask.com, Gigablast
Search services maintain search engines—programs that users can use to ask questions or use keywords to find information

20. Tagging
Tags: do-it-yourself labels that people can put on anything found on the internet, from articles to photos to videos
Can be shared easily with other people
Tags are available through
delicious.com, BlinkList, Flickr

21. 2.4 The Online Gold Mine

22. Internet Telephony
Uses the Internet to make phone calls via VoIP (Voice over Internet Protocol)
Long-distance calls are either very inexpensive or free
With a PC that has a sound card, microphone, Internet connection with modem & ISP, and internet telephone software such as Skype and Vonage
Also allows videoconferencing

23. E-Commerce
E-Commerce (electronic commerce): conducting business activities online
B2B commerce is business-to-business e-commerce
Online finance involves online banking, stock trading online, and e-money such as PayPal
Online auctions link buyers with sellers (e.g., eBay)
Online job hunting match job hunters with employers
Discussion Question: Have you every sold anything on eBay? Used PayPal? Did you have any problems? What would you warn people about?

24. Web 2.0
The move toward a more social, collaborative, interactive, and responsive web; has led to the “social web,” giving rise to:
Social networking sites: Facebook, MySpace
Social networking website: an online community that allows members to:
Keep track of friends
Share photos, videos, music, stories, and ideas
Media-sharing sites: YouTube, Flicker, Shutterfly, etc.
Media-sharing website: type of online social network in which members share media such as photos, videos, music, ideas, and so forth

25. 2.5 The Intrusive Internet

26. Malware refers to software programs designed to damage or do other unwanted actions on a computer system.
Spamming
Cookies

27. Spam: Electronic Junk Mail
Unsolicited that takes up your time
Delete it without opening the message
Never reply to a spam message
When you sign up for something, don’t give your address
Use spam filters
Fight back by reporting new spammers to or

28. Cookies Little text files left on your hard disk
by some websites you visit
Can include your log-in name, password, and browser preferences
Can make visiting these websites next time more convenient and faster
But cookies can be used to gather information about you and your browsing habits; this information can be used without your consent