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

Telephone Modem See panel 2.3 on page 39

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 Other wireless connections 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

Joe_Black@earthlink.net.us E-mail Addresses User ID Domain Name Domain Abbreviations: .com Commercial businesses .edu Educational and research institutions .gov U.S. government agencies and bureaus .int International organizations .mil U.S. military organizations .net Internet network resources .org Nonprofit and professional organizations Domain Top-level domain Country (location) (domain type)

E-mail Attachments Instant messaging 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

Netiquette Use FAQs Avoid flaming Don’t shout Avoid sloppiness Make attachments small Quote only relevant portion when replying Avoid spams

World Wide Web Uses of the WWW Why the WWW is inviting & easy to use 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 Web pages Browsers 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 HTML (hypertext markup language) HTTP 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 Plug-ins – also called a player or a viewer - is a program that adds a specific feature to a browser, allowing it to play or view certain files Helper applications – or add ons; runs multimedia elements separate from the browser Multimedia development Applets – small programs that can be quickly downloaded and run by most browsers Java – complex programming language that enables programmers to create animated and interactive web pages JavaScript & ActiveX – may be used to create activities such as scrolling banners and pop-up menus Animation – the rapid sequencing of still images to create the appearance of motion Streaming video - the process of transferring data in a continuous flow so that you can begin viewing a file even before the end of the file is sent Streaming audio – allows you to listen to a file while the data is still being downloaded

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