Chapter 2 The Internet and World Wide Web

The Internet What are some services found on the Internet? p Fig Chat (4) (1) 1. (2) 2. Web (3) 3. File transfer (5) 5. Message board (6) 6. Instant messaging (AIM, MSN, Yahoo, ICQ)

History of the Internet How did the Internet originate? p  ARPANET: Networking project by Pentagon’s Advanced Research Projects Agency (ARPA) ---To allow scientists at different locations to share information ---can function even if part of network were destroyed by a disaster  ARPANET became functional in September  Four main computers: UCLA, UCSB,Stanford,UU

History of the Internet How has the Internet grown? p Today More than 150 million host nodes 1984 More than 1,000 host nodes 1969 Four host nodes

History of the Internet Who controls the Internet? p World Wide Web Consortium (W3C)  Oversees research, sets standards and guidelines Internet2 (I2)  Internet-related research and development project  Develops and tests advanced Internet technologies  No one c — c it is a public, cooperative, and independent network  Several organizations set standards

How can you connect to the Internet? 1. Dial-up access modem in your computer uses a standard telephone line to connect to the Internet. 2. Integrated Services Digital Network (ISDN) replaced by 3. Digital subscriber line (DSL) provide connections using regular copper telephone lines. 4. Cable Modem taking advantage of unused bandwidth on a cable television network.

How can you connect to the Internet? Dial-upDSLCable TV Speed 56 Kbps128 Kbps to Mbps 200Kbps~1.5Mbps or more Price $6~$20/ month $20~$50/ month $20~$50/ month Connection Establish connection each time you log on always on—whenever the computer is running EvaluationSlow but inexpensive High speed but cost about twice as much as dial-up

How the Internet Works What are the ways to access the Internet? p Fig Internet Service Provider (ISP) Regional ISP: National ISP : AT&T and EarthLink provide: internet access (dial-up,DSL, cable) 2. Online Service Provider (OSP) like AOL and MSN provide: internet access and many members-only features 3.Wireless Internet Service Provider (WISP) like AT&T wireless and Vorizon wireless provide: internet access

How the Internet Works How might data travel the Internet using a telephone line connection? p Fig. 2-3 Step 1. Request data from a server on Internet Step 5. Regional ISP uses leased lines to send data to a national ISP Step 6. National ISP routes data across the country Step 8. Server sends data back to you Step 2. Modem converts digital signals to analog signals Step 3. Data travels through telephone lines to a local ISP Step 4. Data passes through routers Step 7. National ISP passes data to local ISP

What Is the World Wide Web ? The internet is a network of computer networks worldwide The web is a tool used to retrieve information published on the internet To navigate the web we use a browser such as Netscape or internet explorer(IE)

Internet Software: The Client-server Partnership Two pieces of software that work together Client: software application on user’s computer Client retrieves, displays information for user Server: stores and sends information to clients as requested

The World Wide Web What is a Web browser? p Microsoft Internet Explorer Netscape Mozilla  Program that allows you to view Web pages Firefox

Internet Addresses What is a URL (Uniform Resource Locator)? p Fig. 2-8 Unique address for a Web page A web server delivers the Web page to your computer

The World Wide Web What is downloading? p  The process of a computer receiving information  Depending upon connection speed, downloading can take from a few seconds to several minutes

The World Wide Web How can you establish a connection and start the Web browser? p Fig. 2-6 Step 2. If necessary, connect to the Internet Step 3. Connection to the Internet occurs, and a home page displays Step 1. Click the Web browser program name

The World Wide Web How do handheld computers and cellular telephones access the Web? p Fig. 2-7  Must be Web-enabled  Use a microbrowser that displays Web pages that contain mostly text

How the Internet Works What is a domain name? p Figs. 2-4 – 2-5  Text version of Internet protocol (IP) address  Number that uniquely identifies each computer or device connected to Internet Domain name: IP:

Keeping the Web Straight: Document Addresses Address format: Eg., Address must be exact, i.e. Upper and lower case letters make a difference.Edu,.Com,.Org,.Gov, ~ HTTP: hypertext transfer protocol Document type for all web documents HTML: hypertext markup language Language for creating web documents

How to Check your IP address p Figs. 2-4 – 2-5  Check your own IP address Start ---all programs ---Accessories—Command Prompt Type “ ipconfig /all”.  Check what is the IP address Start ---all programs ---Accessories—Command Prompt Type “ping

Hypertext Links Highlighted words or text in a WWW document Moves you to a place within same document, or to a web page elsewhere Previous page

What Is a Web Site? an electronic document stored on a web server uses HTML (Hypertext Markup Language) may include text, sound, animation, images usually has links to other Web pages or different parts of the same Web site

What Is a Home Page? The first web page you see when you access a web site Usually provides means of moving to other areas at that web site (directory, table of contents)

Who Provides Internet Information?  Non-profit: governments, universities, libraries, non-profit groups  Commercial information providers  Self-publishers (personal home pages)  Only a fraction of what is available is on the web

Using the World Wide Web Allows you to browse a wide variety of internet sources Instantaneous connections to internet sites world wide AdvantagesDisadvantages Connections can be slow or busy No standard methods of organization Out-of -date materials may not be removed Contents can be (maliciously) altered Sites can simply be moved/removed

What Affects the Speed of Transmission?  Phone lines are “slower” than ethernet wires Speed of modem: speed of data transmission (BPS) Modems transmit at 28,800, 33,600 and 56k baud  Traffic on the internet  The power of your PC  The data being transmitted

Error Messages Do Happen An error message can appear in a window on your screen, because The URL may be incorrect The site may have “moved” The communication lines may be busy SO retype the URL or try again later

IE Menu Bar FILE: for working with files (similar to word processing) EDIT: for editing page content and setting preferences VIEW: for options on viewing page content Favorites: Save your favorite websites Tools: configuration your IE HELP:

IE Toolbar = Quick Navigation Back and Forward - for short jaunts Refresh - get current page again Home - go back to the first screen that appears after logging on Search - access to internet search engines History-the web sites visited before backforward refreshhome history Tool bar customize: 1. Let the mouse point to toolbar 2. click right button of mouse 3. Click “customize..”

Assignment 1 v Satisfying the requirement v Concise and clear description and explanation

A Brief Word on Searching There are four main ways to find information on the internet: Using an address (URL) Net surfing (jumping from link to link) Using subject directories like yahoo Using search engines like Google

Try Searching Search engines: 1. Open 2. Click “Advanced Search ”Advanced Search 3. Input “computer”, -- Any Web site name that is listed as the result of a search What is a hit?

The World Wide Web What is a search engine?  Program used to find Web sites and Web pages by entering words or phrases called search text  Also called a keyword

The World Wide Web What is a subject directory?  Search tool with organized set of topics and subtopics  Lets you find information by clicking links rather than entering keywords

The World Wide Web What are the eight basic types of Web sites?  Portal  News  Informational  Business/marketing  Educational  Entertainment  Advocacy  Personal

The World Wide Web What is a portal?  A Web site that offers a variety of services from one, convenient location, usually for free  Searching, sports, , news, weather, auctions,

Example: 1. open “maps.yahoo.com” 2. Click “Driving Directions” 3. In A, Input “34 peachtree street” Input “atlanta,30303” 4. In B, Input your home address

The World Wide Web What is a news Web site?  Contains newsworthy material  Stories and articles relating to current events, life, money, sports, and weather

The World Wide Web What is an informational Web site?  Contains factual information  Created by organizations and government agencies

The World Wide Web What is a business/marketing Web site?  Contains content that promotes products  Allows you to purchase products or services online

The World Wide Web What is an educational Web site?  Some companies offer online training for employees  Some colleges offer online classes and degrees  Offers avenues for formal and informal teaching and learning

The World Wide Web What is an entertainment Web site?  Offers an interactive environment featuring music, video, sports, games, and more

The World Wide Web What is an advocacy Web site?  Contains content that describes a cause, opinion, or idea

The World Wide Web What is a personal Web site?  Web page maintained by private individual  Reasons: sharing life experience with the world or job hunting

The World Wide Web What is multimedia?  Application integrating text with other media elements  Graphics  Animation  Audio  Video  Virtual reality

The World Wide Web What graphics formats are used on the Web? BMP GIF (pronounced JIFF) JPEG or JPG (pronounced JAY-peg) PCX PNG (pronounced ping) TIFF

The World Wide Web What is a thumbnail?  Small version of a larger graphic image c —used to improve Web page display time  Usually click on thumbnail to display larger image

The World Wide Web What is audio?  Music, speech, or any other sound  Individual compressed sound files that you download from the Web to your computer  Common Web audio file formats are MP3, WAV, WMA (Windows Media Audio), MPEG, RealAudio, and QuickTime  Once downloaded, you can play (listen to) the contents of the files

The World Wide Web What is streaming audio?  Transfers data in a continuous and even flow  Enables you to listen to the sound as it downloads to your computer  Radio stations use streaming audio to broadcast over the Web

The World Wide Web What is video?  Consists of full-motion images with sound played back at various speeds  MPEG (Moving Pictures Experts Group) is popular video compression standard

The World Wide Web What is virtual reality (VR)?  Use of computers to simulate real or imagined environment  Appears as a three dimensional (3-D) space  Used for games and many practical applications

The World Wide Web What are plug-ins?  Programs that extend the capability of a browser  You can download many plug-ins at no cost from various Web sites Plug-in ApplicationWeb Address Acrobat Readerwww.adobe.comwww.adobe.com Flash Playermacromedia.com Liquid Playerliquidaudio.com QuickTimeapple.com RealOne Playerreal.com Shockwave Playermacromedia.com Windows Media Playermicrosoft.com

Business to business (B2B) Business providing goods and services to other businesses Consumer to consumer (C2C) One consumer sells directly to another Electronic Commerce What is e-commerce? Business to consumer (B2C) Sale of goods to general public  Short for electronic commerce  Business transaction that occurs over the Internet

Other Internet Services What is ?  Short for electronic mail  The transmission of messages and files via a computer network  Messages can consist of simple text or can contain attachments, such as documents, graphics, or audio/video clips  Internet access providers usually provide an program  Some Web sites—such as MSN Hotmail and Yahoo!—provide free services  One of the original services on the Internet

Other Internet Services How do you send an message? Step 1. Start an program (Microsoft Outlook, for example) Step 2. Click the New Mail Message button Step 3. Enter the recipient’s address, the subject, and the message Step 4. Click the Insert file button if you want to attach a picture, for example, and click Send Step 5. The recipient opens the message

Other Internet Services How does an message travel? Step 1. Using software, you create and send message Step 2. Your software contacts software on your ISP’s outgoing mail server Step 4. When recipient uses software to check for messages, the message transfers from incoming mail server to recipient’s computer Step 3. Software on outgoing mail server determines best route for data and sends message, which travels along Internet routers to recipient’s incoming mail server

Other Internet Services What is a mailing list?  Group of addresses given a single name  When a message is sent to the mailing list, everyone on the list receives the message  To add your name to a mailing list you must subscribe to it; to remove your name you must unsubscribe

Other Internet Services What is FTP?  File Transfer Protocol—Internet standard that allows you to upload and download files with other computers on the Internet

Netiquette What is netiquette? Golden Rule: Treat others as you would like them to treat you.  Code of acceptable behaviors users should follow while on the Internet

Web Publishing What is Web publishing? Step 1. Plan the Web site Step 2. Analyze and design the Web site Step 3. Create the Web site Step 4. Deploy the Web site Step 5. Maintain the Web site  Development and maintenance of Web pages

Summary of the Internet and World Wide Web History of the Internet How to access and connect to the Internet The World Wide Web Electronic commerce Other Internet services Netiquette Web publishing Chapter 2 Complete