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© 2011 The McGraw-Hill Companies, Inc. All rights reserved.

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The Internet & the World Wide Web


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2.1 Connecting to the Internet

Internet History Began with 1969’s ARPANET for US Dept. of Defense 62 computers in 1974 500 computers in 1983 28,000 computers in 1987 Early 1990s, multimedia became available on internet

To connect you need An access device (computer with modem) A means of connection (phone line, cable hookup, or

wireless) An internet access provider


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Definition: Bandwidth is an expression of how much data – text, voice, video and so on – can be sent through a communications 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.


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Physical connection to internet—wired or wireless Telephone [dial-up] modem High-speed phone line—ISDN, DSL, T1 Cable modem Wireless—satellite and other through-the-air links


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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 a 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


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Narrowband (Dial-Up Modem) Telephone line narrowband, or low bandwidth, low speed Dial-up connection—use of telephone modem to connect

to internet Telephone Modems

Can be either internal or external Most ISPs offer local access numbers Need call waiting turned off; either manually or in

Windows


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2.1 The Modem Connection


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High-Speed Phone Lines ISDN line

Allows voice, video, & data transmission over copper phone lines Can transmit 64 to 128 Kbps

DSL line Uses regular phone lines, DSL modem Receives data at 1.5-10 Mbps; sends at 128Kbps – 1.5 Mbps Need to live within 3.3 miles of phone company switching office

T1 line—very expensive Traditional trunk line; carries 24 normal telephone circuits Transmission rate of 1.5 to 6 Mbps Cable modem TV cable system with internet connection Receives data at up to 30 Mbps; sends at 1.4 Mbps


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How long to Download a 6-Minute Video? 28.8 Kbps telephone—4 ¾ hours ISDN line—1hour DSL line—11 minutes Cable modem—2 minutes T1 line--instantaneously


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Satellite Wireless Connection Transmits data between satellite dish and satellite

orbiting earth Sends data at around 512 Kbps; receives at 1.5 Mbps Connection is always on Requires internet access provider with 2-way satellite

transmission


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Other Wireless Connections: Wi-Fi & 3G Wi-Fi—stands for “wireless fidelity”

Name for a set of wireless standards (802.11) set by IEEE Transmits data wirelessly for 300 – 500 feet from access point

(hotspot) Typically used with laptops that have Wi-Fi hardware

3G—stands for “third generation” High-speed wireless that does not need access points Used in PDAs and smartphones Can deliver downloadable video clips, hi-res games


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Internet Access Providers—Three Types Internet Service Provider (ISP)—e.g., Earthlink

Company that links online users to its servers, which link users to the internet through another company’s network

Commercial Online Service—e.g., AOL Members-only company that provides specialized content

as well as internet access Wireless Internet Service Provider (WISP)—e.g.,

Cingular, Sprint Enables wireless laptop and smartphone users to access internet


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2.2 How Does the Internet Work?

The internet consists of thousands of smaller networks Central to this arrangement are Client/Server networks

Client: a computer requesting data or services Server or host computer: a central computer supplying

data or services requested of it


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Internet Connection: POP, NAPs, Backbone, & Internet2 Point of Presence (POP)

A collection of modems and other equipment in a local area A local gateway to the ISP’s network ISP connects to a network access point

Network Access Point (NAP) A routing computer at a point on the internet where several

connections come together NAPs are owned by network service providers (e.g., MCI) PNAPs provide more efficient routing of data [continued]


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Internet Backbone High-speed, high-capacity data transmission lines Uses the newest technology Providers include AT&T, Sprint, Verizon, GTE, Teleglobe,

and Deutsche Telekom Internet 2

Cooperative university/business research project Adds new “toll lanes” to older internet to speed things up Advances videoconferencing, research, collaboration


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Handshaking & Authentication: Connecting Your Modem to ISP Handshaking—fastest transmission speed established Authentication—correct password & user name

Protocols The set of rules a computer follows to electronically transmit data. TCP/IP is the internet protocol

Developed in 1978 Used for all internet transactions

Packets Fixed-length blocks of data for transmission Data transmissions are broken up into packets


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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 Each number is between 0 and 255 Example: 95.160.10.240 Dynamic IP addresses change with every use Static IP addresses don’t change


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Who runs the internet? The board of trustees of the Internet Society (ISOC)

oversees the standards Internet Corporation for Assigned Names and Numbers

(ICANN) regulates domain names


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2.3 The World Wide Web

Browsers Software for web-surfing Examples: Internet Explorer, Mozilla FireFox, Apple

Macintosh’s Safari, Google’s Chrome, Microsoft’s Bing Website

The location on a particular computer that has a unique address

Example: www.barnesandnoble.com, www.mcgraw-hill.com The website could be anywhere--not necessarily at company

headquarters


Discussion Question: What type of internet browser do you think is the best? Have you used others?

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Web Page A document on the web that can include text, pictures,

sound, and video The first page on a website in the Home page The Home page contains links to other pages on the

website


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Uniform Resource Locator (URL) A character string that points to a specific piece of

information anywhere on the web A website’s unique address It consists of

The web protocol, http The domain name of the web server The directory name or folder on that server The file within the directory, including optional extension


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TCP/IP—Internet Protocol HTTP—Protocol Used to Access World Wide Web Hypertext Markup Language (HTML)

The 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


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2.3 The World Wide Web Web Browsers

Your tool for using the internet Comes preinstalled on most PCs 5 basic elements

Menu bar Toolbar URL bar Workspace Status bar


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2.3 The World Wide Web Home Page

The page you see when you open your web browser You can change the Home Page on your browser

Back, Forward, Home & Search Use the menu bar

icons to move from one page to another


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Navigation History Lists

A list of websites you visited since you opened up your browser for this session

Allows you to easily return to a particular site


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Navigation Bookmarks

Allows you to store the URL from a site on your computer so you can find it again in another browser session

To save the URL for a site, click on “Favorites” in Internet Explorer or “Bookmarks” Mozilla Firefox


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Navigation—Three Ways to Interact with Any Given Web Page Use mouse to click on hyperlink, which will transfer you

to that page Radio buttons: little circles located in front of various

options Search box: used for entering

text in a fill-in text box, then hitting enter


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Navigation Scroll arrows: small up/down and left/right arrows that

when clicked on, move the screen so that you can see the rest of the web page

Frame: an independently controllable section of a web page


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Web portals A gateway website that offers a broad array of resources

and services, online shopping malls, email support, community forums, stock quotes, travel info, and links to other categories

Examples: Yahoo!, Google, Bing, Lycos, and AOL Most require you to log in, so you can

Check the Home page for general information Use the subject guide to find a topic you want Use a keyword to search for a topic


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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 Databases of search engines are compiled using software programs

called spiders Spiders crawl through the World Wide Web Follow links from one page to another Index the words on that site


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Search Services & Search Engines A search by a single search engine never covers the

entire web Search engines differ in what they cover


Discussion Question: Do you prefer one search engine for finding information? Why?

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2.3 The World Wide Web 4 Web Search Tools

1. Individual Search Engines Compile their own searchable database on the web You search by typing keywords and receiving “hits” Examples are Ask, Bing, Google, and Yahoo!

2. Subject Directories Created and maintained by human editors, not electronic

spiders Allow you to search for information by selecting lists of

categories or topics Example sites are Beaucoup!, Galaxy, Google Directory,

LookSmart, Open Directory Project, and Yahoo! Directory


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4 Web Search Tools3. Metasearch Engines

Allows you to search several search engines simultaneously

Examples are Clusty, Dogpile, Grokker, Mamma, MetaCrawler, and Webcrawler

4. Specialized Search Engines Help locate specialized subject matter, such as info on

movies, health, jobs Examples are Career.com. WebMD, Expedia


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Smart Searching: Three General Strategies If you’re just browsing . . .

Try a subject directory Next try a metasearch engine

If you’re looking for specific information . . . Try a Answers.com “one-click” search Or go to a general search engine, then a specialized one

If you’re looking for everything on a subject . . . Try the same search on several search engines


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2.3 The World Wide Web Multimedia Search Tools

Still images—e.g., Google Image Search Audio—e.g., Yahoo! Audio Search Video—e.g., AllTheWeb Multiple sources, including music—e.g., A9, Rocket Music Song ID

(cellphones) Scholarly—e.g., Google Scholar


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Desktop Search Desktop search engine: a tool that extends searching

beyond the web to the contents of your computer’s hard disk

Uses technology similar to that in web search engines Offered by all of the principal search engine services as a

download


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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 del.icio.us, BlinkList, Flickr


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2.4 Email & Other Ways of Communicating over the

Net Email Program

Enables you to send email by running email software on your computer that interacts with an email server at your internet access provider

Incoming mail is stored on the server in an electronic mailbox

Upon access, mail is sent to your software’s inbox Examples: Windows Mail (Outlook), Apple Mail


Discussion Question: If your email is stored at the server and servers are backed up, when you delete an email is it gone for

good?

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Net Web-Based Email

You send and receive messages by interacting via a browser with a website

Advantage: You can easily send and receive messages while traveling

Examples: Yahoo! Mail, Windows Live Hotmail, Gmail (Google), and AOL Mail


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Net Using email

1. Get an email address, following the format


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Net Tips for Using Email

1. Type addresses carefully, including capitalization, underscores, and periods

2. Use the reply command to avoid addressing mistakes

3. Use the address-book feature to store email addresses

4. Deal with each email only once

5. Don’t “bloat” you email

To keep email, use filters (Instant organizer

folders)© 2011 The McGraw-Hill Companies, Inc. All rights reserved.

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Net Email Attachments

A copy of a file or document that you send attached to an email to one or more people

The recipient must have compatible software to open the attachment. If they don’t have Excel, they probably can’t read the spreadsheet you sent them. Be careful about opening attachments Many viruses hide in them Know who is sending it to you before you open it


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Net Instant Messaging

Any user on a given email system can send a message and have it pop up instantly on the screen of anyone logged into that system

To get IM: download IM software from a supplier Examples: AOL/AIM, Google Talk, MySpace, Facebook,

and Yahoo! Messenger The downside of IM:

Lack of privacy Lack of common standards Time wasters


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Net FTP – File Transfer Protocol

A software standard for transferring files between computers, including those with different operating systems

You can transfer files from an FTP site on the internet to your PC

FTP sites offer many free files FTP sites may be either public or proprietary You can download using your web browser or FTP client

programs


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Net Newsgroups

A giant electronic discussion board There are thousands of free internet newsgroups Usenet is the worldwide public network of servers on the

internet www.usenet.com To participate you need a newsreader

Listserv An email-based discussion group Uses an automatic mailing-list server that sends email to

subscribers on selected topics


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Net Real-Time Chat (RTC) Participants have a typed discussion while online at the

same time RTC involves message board, with many contributions

(“posts”) To start, user service on your browser, such as IRC IM is one-on-one, but RTC has a list of participants


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Net Netiquette – Appropriate Online Behavior Before you ask a question, consult the FAQs Avoid flaming Don’t SHOUT – use all capital letters Be careful with jokes Avoid sloppiness, but avoid criticizing other’s sloppiness Don’t send huge file attachments unless requested When replying, quote only the relevant portion Don’t “overforward”


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Net


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2.5 Telephony, Multimedia, Webcasting, Blogs, E-Commerce,

& the Social Web Internet Telephony

Uses the internet to make phone calls Long-distance calls are either very inexpensive or free

With no PC, dial a special phone number to packetize your call

With a PC that has a sound card, microphone, Internet connection, and internet telephone software such as Microsoft NetMeeting and Windows Messenger

Sound quality is no longer an issue Also allows videoconferencing


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& the Social Web Multimedia on the Web

Allows you to get images, sound, video, and animation May require a plug-in, player, or viewer

A program that adds a specific feature to a browser so it can view certain files

Example: Adobe Acrobat Reader, RealPlayer, QuickTime Multimedia Applets

Small programs that can be quickly downloaded and run by most browsers

Java is the most common Applet language Microsoft’s Visual Studio.NET competes with Java Text & Images: great variety available Example: Google Earth


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& the Social Web Multimedia on the Web (continued)

Animation The rapid sequencing of still images to create the

appearance of motion Used in video games and web images that seem to move

Video Streaming video transfers data in a continuous flow so you

can begin viewing a file before it is all sent Example is RealPlayer

Audio may be transmitted either: Downloaded completely before the file can be played, or Downloaded as streaming audio


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& the Social Web Push Technology & Webcasting

Push technology, software that automatically downloads information to personal computers

Webcasting is sending of customized text, video, audio on regular basis

Blogging—RSS, XML, & the Rise of the Blogosphere RSS newsreaders: programs that scour the web and pull

together in one place “feeds” from several websites Based on XML (extensible markup language): a web-document

tagging and formatting language XML and RSS have led to blogs and bologosphere Blog: short for web log, a diary-style web page Have become popular, both privately and in politics


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& the Social Web Podcasting

Recording internet radio or similar internet audio programs

E-Commerce: conducting business activities online B2B commerce is business-to-business e-commerce Online finance now involves online banking, stock trading

online, and e-money such as PayPal Online auctions link buyers with sellers Online job hunting match job hunters with an employer


Discussion Question: Have you every sold anything on eBay? Used PayPal?

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& the Social Web Matchmaking websites

Also called “dating” websites, are online forums that people may join in hopes of meeting compatible potential mates

Examples: AmericanSingles, eHarmony, Match.com


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& the Social Web Web 2.0 & the social web

Web 2.0: the move toward a more social, collaborative, interactive, and responsive web

MySpace, Facebook, & other social-networking sites Social networking website: an online community that allows

members to: Keep track of friends Share photos, videos, music, stories, and ideas

YouTube, Flicker, and other media-sharing sites Media-sharing website: type of online social network in

which members share media such as photos, videos, and music


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& the Social Web Friendfeed, Spokeo, & other social-network

aggregators Social-network aggregators: collect content from all of a user’s

various social network profiles into one place, then allow him or her to track friends and share other social network activities

Twitter & Tumbler social networking & microblogging services “Thoughtcasting” or “microblogging”: sending a text message

from your mobile phone to friends’ web/IM or their phones Tumbler allows the use of multiple media


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2.6 Snooping, Spoofing, Phishing, Pharming, Cookies, & Spyware

Not everyone on the internet is honest We consider some ways that others can be intrusive Snooping

Email is not private Corporate management has the right to view employees’

email Friends can send email anywhere Not all ISPs protect their customers’ privacy


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Spam: Electronic Junk Mail Unsolicited email 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 email

address Use spam filters Fight back by reporting new spammers to www.abuse.net

or www.spamhaus.org or www.rahul.net/falk


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2.6 Snooping, Spoofing, Phishing, Pharming, Cookies, & Spyware Spoofing

Using fake email sender names so the message appears to be from a different source, so you will trust it.

If you don’t know the sender, don’t open it. Phishing

Sending forged email directing recipient to fake website Purpose: to entice people to share personal or financial

data Fake website looks like real website—e.g., Citibank’s


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Pharming Thieves implant malicious software on your PC. Redirects you to an imposter web page even when you

type the correct URL To foil it, type the URL with https for “http secure”)—e.g.,

https://www.microsoft.com. Use this one with https, not

http://www.microsoft.com. Since it has only http, it could be spoofed.


Discussion Question: Have you ever been a victim of any of these attacks? If yes, what did you do?

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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


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Spyware Software surreptitiously installed on your computer via

the web Spyware hides on your PC and captures information

about what is on the PC, such as keystrokes, passwords


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Common Forms of Spyware Adware—tracks your web surfing, sends you unsolicited

pop-up ads Browser hijackers—change your browser settings,

replace your Home page Search hijackers—intercept legitimate search requests,

send you to phony websites Key loggers—record all your keystrokes, send them

elsewhere


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Spyware [continued] To prevent spyware, install and use antispyware software

at all times Be careful about free and illegal downloads, since they

are a source of spyware Don’t say “I agree” when you are downloading something

—read the fine print Beware of unsolicited downloads


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Documents

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internet connection

internet internet history

internet definition

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