200 likes | 216 Views
The Internet & the World Wide Web. Chapter 2 Exploring Cyberspace. Chapter 2: Key Questions. 2.1 What are the means of connecting to the Internet, and how fast are they? 2.2 What are the three types of Internet service provider, and what kinds of service do they provide?
E N D
The Internet & the World Wide Web Chapter 2 Exploring Cyberspace
Chapter 2: Key Questions 2.1 What are the means of connecting to the Internet, and how fast are they? 2.2 What are the three types of Internet service provider, and what kinds of service do they provide? 2.3 What are the components of an e-mail address, and what are netiquette and spam? 2.4 What are Web sites, Web pages, browsers, URLs, and search engines? 2.5 What are FTP, Telnet, newsgroups, real-time chat, and e-commerce?
To Access the Internet, You Need… • An access device • A physical connection • An Internet Service Provider (ISP) Can you give examples of each?
Physical Connection • Telephone (dial-up) modem • Several high-speed phone lines • ISDN • DSL • T1 • Cable modem • Wireless
Data Transmission Speeds • Upload – data from local computer to remote • Download – data from remote to local • Bandwidth • Data that is sent through a communications channel in a given amount of time • Data transmission speeds: • Bps – bits per second • Kbps – kilobits per second • Mbps – megabits per second • Gbps – gigabits per second • 8 bits = 1 byte = 1 character
High Speed Phone Lines • ISDN (Integrated Services Digital Network) • Hardware & software • Uses traditional telephone lines (128 Kbps) • DSL (digital subscriber line) • Always on • Transmission rate is consistent (1.5-8.4 Mbps) • Must live within 3.3 miles of a phone company switching office • T1 line (1.5 Mbps) • Used by corporate, government, and academic sites
Cable Modems • Connects a PC to a cable-TV system that offers Internet access • Always on • Competes with DSL • Transmission rate may not be consistent during peak hours • Speed:10 Mbps
Wireless Systems • Communications satellite • Radio waves (microwaves) transmitted from earth-based stations • Receives data at 400 Kbps & sends data at 56 Kbps (with phone line) • Other wireless connections • Radio waves for cellular phones • Sends data up to 155 Mbps
Three Types of ISP Services • Free-service providers • NetZero, AltaVista, BlueLight.com • Advertisements and personal info • Basic-service providers • Offer local connection • Full-service providers • AOL, Earthlink, MSN • More technical support and international access
How to Get E-mail Software? • Purchase • MS Outlook express, Lotus Notes • Get as a part of other package • Netscape Communicator • Provided by your ISP • AOL • Free Email Services • Yahoo, Hotmail
E-mail Addresses User ID Domain Name Joe_Black@earthlink.net.us Domain Top-level domain Country (location) (domain type)
E-mail • Attachments • Attached to emails • Formatting preserved • Recipient must have software to read them • Instant messaging • Cross between e-mail and phone • Message pops up instantly on the screen if user is logged on
Use FAQs Avoid flaming Don’t shout Avoid sloppiness Make attachments small Quote only relevant portion when replying Avoid spams Netiquette
World Wide Web • Uses of the WWW • E-mail • Entertainment • E-commerce • E-tailing, auction, online finance, on-line job hunting, B2B • Why the WWW is inviting & easy to use • Multimedia format : graphics, video, audio, text • Use of hypertext
Web Terms • Web site • a computer with a domain name is called a site • Web pages • a document that can include text, pictures, sound, and video • Browsers • software that enables users to view Web pages URLs • URLs (Universal Resource Locator) • a string of characters that point to a specific Web page • Web portals • Web sites that group together popular features
Web Terms • Multimedia format • graphics, video, audio, text • HTML (hypertext markup language) • A language used to specify document structure, formatting, and links to other documents • HTTP • hypertext transfer protocol –rules that allow browsers to connect with Web servers
Search Engine Types • Human-organized search sites • subject experts (humans) do the indexing • Yahoo!. AOL, MSN, Netscape, Lycos • Computer-created search sites • software "spiders" (software) do the indexing • Northern Light, Excite, WebCrawler, FAST Search, Inktomi • Hybrid search sties • humans supplemented by computer indexes • AskJeeves, Direct Hit, Go, GoTo.com, Google, HotBot, Snap • Metasearch sites • sends query to other search tools and compile the results • Go2Net/MetaCrawler, SavvySearch, Dogpile, Inference
Multimedia on the Web • Plug-ins & helper applications • Multimedia development • Applets, Java, JavaScript, ActiveX • Text and images • Animation • Video • Audio
More Internet Resources • FTP – File Transfer Protocol • a program that can transfer files to one compute to another • Telnet • a program that allows you to connect to remote computers on the Internet • Newsgroups • a giant electronic bulletin board on which users conduct written discussions about a specific subject • Real-time chat • participants have a typed discussion while online at the same time