Discovering Computers – Chapter Two Using the Internet

History of the Internet How did the Internet originate? Next p. 69 Goal: To function if part of network were disabled Became functional September 1969 ARPANET Networking project by Pentagon’s Advanced Research Projects Agency (ARPA) Goal: To allow scientists at different locations to share information

History of the Internet How has the Internet grown? What do we call hosts today? p. 69 Today More than 500 million host nodes 1984 More than 1,000 host nodes 1969 Four host nodes Next

Who controls the Internet?? p. 70 World Wide Web Consortium (W3C)  Oversees research, sets standards and guidelines  Mission is to contribute to the growth of the Web  Nearly 400 organizations around the world are members of the W3C Next  No one c — c it is a public, cooperative, and independent network  Several organizations set standards Click to view Web Link, click Chapter 2, Click Web Link from left navigation, then click W3C below Chapter 2

High-speed connection Slow-speed technology How the Internet Works How can you connect to the Internet? p. 70 Next Dial-up access modem in your computer uses a standard telephone line to connect to the Internet DSL, cable modem, FTTP, fixed wireless, wireless modem, Wi-Fi, and satellite modems Connection is always on— whenever the computer is running Connection must be established each time you log on.

How the Internet Works How might data travel the Internet using a cable modem connection? p. 73 Fig. 2-3 Next

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

The World Wide Web What is a Web browser ? p. 75 Next  Program that allows you to view Web pages How does a search engine work?  Let’s REVIEW the Browsing the Web worksheet together –  What is Boolean logic?  What engine provided the most results?  Which engine do you prefer to use? What is a home page?  The first page of a website.  It usually provides HYPERLINKS to other pages.

The World Wide Web What is a URL? p Fig. 2-8 Next Unique address for a Web page A web server delivers the Web page to your computer. URL – Uniform Resource Locator

Searching The World Wide Web PRESEARCH – get a definition that helps you choose keywords that will narrow your search results! OBJECTIVE – just the facts SUBJECTIVE – opinions OUTDATED/IRRELEVANT – old/not on topic COMMERCIAL – business

The World Wide Web What are the guidelines for evaluating the value of a Web site? p. 84 Fig Next AffiliationAudienceAuthorityContent CurrencyDesignObjectivity

Technical and Visual Aspects Does the page take a long time to load? Do any pictures or photographs on the page add to the information? Is the spelling correct on the page? Are there headings and subheadings on the page? If so, are they helpful? Is the page signed by the author? Is the author's address included? Is there a date on the page that tells you when it was last updated? If so, is it current? Is the format standard and readable with your browser? Is there an image map (large clickable graphic with hyperlinks) on the page? On supporting pages, is there a link back to the home page? Are the links clearly visible and annotated or explanatory? Are there photographs or sound files on the page? If so, can you be sure that a picture or sound has not been edited? If you're not sure, should you accept the information as valid for your purpose?

Content Is the title of the page indicative of the content? Is the purpose of the page indicated on the home page? When was the document created? If there is no date, is the information current? Does up-to-date information matter for your purpose? Is the information useful for your purpose? Would it have been easier to get the information somewhere else? Would information somewhere else have been different? Why or why not? Did the information lead you to other sources, both print and Web, that were useful? Is a bibliography of print sources included? Does the information appear biased? (One-sided, critical of opposing views, etc.) Does the information contradict something you found somewhere else? Do most of the pictures supplement the content of the page?

Authority Who created the page? What organization is the person affiliated with? Conduct a link: command in a search engine to see who links to this page. Can you tell if other experts in the field think this is a reputable page? Does the domain of the page (k12, edu, com, org, gov) influence your evaluation? Are you positive the information is valid and authoritative? What can you do to validate the information? Are you satisfied the information useful for your purpose? If not, what can you do next? If you do a search on the creator of the page, do you find additionalinformation that shows the Web page author is an expert in the field?

The World Wide Web What is a thumbnail? p. 86 Fig Next  Small version of a larger graphic c —used to improve Web page display time  Usually click on thumbnail to display larger graphic

The World Wide Web What is animation? p. 86 Next  Appearance of motion created by displaying a series of still images in sequence

The World Wide Web What is audio? p Fig Next  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 AAC, AIFF, ASF, MP3, WAV, WMA, RA, and QT  Once downloaded, you can play (listen to) the contents of the files  A podcast is recorded audio, usually an MP3 file, stored on a Web site that can be downloaded to a computer or a portable media player

The World Wide Web What is streaming audio? p. 86 Next The process of transferring audio in a continuous and even flow Enables you to listen to music as it downloads to your computer

The World Wide Web What is video? p. 88 Fig Next  Consists of full-motion images, most with sound, that are played back at various speeds  MPEG (Moving Pictures Experts Group) is popular video compression standard Click to view Web Link, click Chapter 2, Click Web Link from left navigation, then click YouTube below Chapter 2

The World Wide Web What is virtual reality (VR)? p. 88 – 89 Fig Next  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? p. 89 Fig Next  Programs that extend the capability of a browser  You can download many plug-ins at no cost from various Web sites

The World Wide Web What is Web publishing? p Fig Next  Development and maintenance of Web pages

Business to business (B2B) Business providing goods and services to other businesses Consumer to consumer (C2C) One consumer sells directly to another E-Commerce What is e-commerce? p Fig Next Business to consumer (B2C) Sale of goods to general public  Short for electronic commerce  Business transaction that occurs over the Internet Click to view Web Link, click Chapter 2, Click Web Link from left navigation, then click PayPal below Chapter 2