Using Information Technology

1. Using Information Technology Chapter 2 The Internet & the World Wide Web

2. The World of The Internet

3. The Internet & the World Wide WebExploring Cyberspace • 2.1 Choosing Your Internet Access Device & Physical Connection: The Quest for Broadband • 2.2 Choosing Your Internet Service Provider (ISP) • 2.3 Sending & Receiving E-Mail • 2.4 The World Wide Web • 2.5 The Online Gold Mine: More Internet Resources, Your Personal Cyberspace, E-Commerce, & the E-conomy

4. 2.1 Choosing Your Internet Access Device & Physical Connection • This section discusses the different technologies used to connect individuals to the internet including: • 1. Access device: a personal computer with a modem • 2. Physical connection: a telephone line

5. Physical connection • The wired or wireless means of connecting to the Internet.

6. Data Transmission Rates • Data is transmitted in bits per second. • bps stands for bits per second. A bit is the smallest unit of information used by computers. A computer with an older modem might have a speed of 28,800 bps per second. • Kbps stands for kilobits per second. This is the most frequently used measure. • Mbps stands for megabits per second • We at NIIT have 1 Mbps leased line for internet • Gbps stands for gigabits per second

7. Bandwidth • - an expression of how much data can be sent through a communications channel in a given amount of time • Broadband - very high speed connection

8. Download & Upload • Download - to transmit data from a remote computer to a local computer • Upload - to transmit data from a local computer to a remote computer

9. Telephone (Dial-Up) Modem: Low Speed but Inexpensive & Widely Available • Modem - device that sends and receives data over telephone lines to and from computers • Most modems today have a maximum speed of 56 Kbps.

10. Packet Switching High-Speed Phone Lines: (No dialup line) • Integrated Services Digital network (ISDN) - hardware and software that allows voice, video, and data to be communicated over traditional copper-wire telephone lines. Speeds up to 128 kbps. • Digital Subscriber Line (DSL) - also uses regular phone lines but much faster than ISDN. Download speeds 1.5 – 8.4 Mbps • One for telephone wire is splitted for voice and one for data. 64kbps is required for human voice data transfer • T1 - A traditional trunk line that carries 24 normal telephone circuits and has a transmission rate of 1.5 Mbps. Good for business. • 23 lines are for usage and 1 is for connectivity control • 23 different phone numbers • In Europe it is 29+1 and is called E1

11. Cable : Close Competitor to DSL Speeds up to 10 Mbps Fiber Optics: Can support speeds up to 2 Gbps High-Speed Lines

12. Wireless Systems: Satellite & Other Through-the-Air Connections • Satellite: With a pizza-size satellite dish on your roof, you can receive data at the rate of 400 Kbps from a communications satellite, a space station that transmits radio waves called microwaves from earth-based stations. • Other wireless connections:In urban areas, some businesses are using radio waves transmitted between towers that handle cellular phone calls, which can send data at up to 155 Mbps.

13. 2.2 Choosing Your Internet Service Provider (ISP) • ISP - a company that connects you through your communications line to its servers, or central computer, which connect you to the Internet via another company’s network access points

14. 2.3 Sending & Receiving E-MailE-Mail Software & Carriers • Buy e-mail software • Get e-mail program as part of other computer software (such as browser) • Get e-mail software as part of your ISP package • Get free e-mail services

15. E-Mail Addresses Domain Name • Jane_Doe@earthlink.net.uk • User name: Jane_Doe • Domain : earthlink • Top-level domain: .net • Two-letter country extension: .uk

16. Attachments • Attachments: Files attached to an e-mail message in their own format. Individuals can attach pictures, sounds, videos, and other files to e-mail message. • Note: Many viruses ride along with e-mail as attached files. Never open an attached file from an unknown source

17. Instant messaging (IM) - allows any user on a given e-mail system to send a message and have it pop up instantly on the screen of anyone else logged onto that system Instant Messaging

18. Chat Applet • A rectangular area containing a document or activity so that users can exchange messages almost instantaneously while operating other programs.

19. Mailing Lists: E-Mail-Based Discussion Groups • List-serves - e-mail mailing lists of people who regularly participate in discussion groups

20. Netiquette: Appropriate Online Behavior • (a) Don’t waste people’s time. • (b) Don’t say anything to a person online that you wouldn’t say to his or her face. • (c)Consult FAQs: Most online groups post FAQs--for Frequently Asked Questions--that explain expected norms of online behavior for a particular group. • (d) Avoid Flaming: Writing an online message that uses derogatory, obscene, or inappropriate language.

21. Netiquette: Appropriate Online Behavior • (e) Emoticons: Keyboard-produced pictorial representations of expressions. • (f) Avoid SHOUTING: Use of all-capital letters is considered the equivalent of SHOUTING. • (g) Avoid Sloppiness: Avoid spelling and grammatical errors. Try to avoid criticizing others’ sloppiness. • (h) Do not send large file attachments, unless requested. This may tie up your country cousin, who has a slow dial-up connection, when he or she badly needs to use it.

22. Netiquette: Appropriate Online Behavior • (i) When replying, quote only the relevant portion. If you’re replying to just a couple of matters in a long e-mail posting, don’t send back the entire message. This forces your recipient to wade through lots of text to find the reference. Instead, edit his or her original text down to the relevant paragraph and then put in your response immediately following.

23. Spam: Unwanted Junk E-Mail • Delete without opening the message • Never reply to a spam message! • Enlist the help of your ISP or use spam filters • Fight back

24. 2.4 The World Wide Web • The Multimedia makes the Web attractive and inviting. • The Hypertext makes the web navigable.

25. Hypertext • A system in which documents scattered across many Internet sites are directly linked, so that a word, phrase or an image in one document becomes a connection to a document in a different place. • The term hypertext was coined by American computer scientist Ted Nelson in 1965 to describe textual information that could be accessed in a nonlinear way. He used the prefix hyper to describe the speed and facility with which users could jump to and from related areas of text.

26. Hypertext Markup Language (HTML) • The set of special instructions (called "tags" or "markups") that are used to specify document structure, formatting, and links to other documents. • HTML is a subset of a broader language called Standard Generalized Markup Language (SGML), which is a system for encoding and formatting documents, whether for output to a computer screen or to paper.

27. HTML Script • <html> • <head> • <script language="javascript" src="http://us.i1.yimg.com/us.yimg.com/i/mc/mc.js"> • </script> • <meta http-equiv="pics-label" content='(pics-1.1 "http://www.icra.org/ratingsv02.html" l gen true for "http://mail.yahoo.com" r ( nz 0 vz 0 lz 0 oz 0 ca 1))'> • <title>Yahoo! Mail - The best free web-based email!</title> • </head> • <body bgcolor=#ffffff • onload="document.login_form.login.focus();"> • <center> • <script language="JavaScript"> • <!-- • hasMsgr = 0; • /*

28. The Web & How It Works • Web-- A domain on the computer • Site - a computer with a domain name • Website - the location of a web domain name in a computer somewhere on the Internet

29. Web page • A Web page is a document on the World Wide Web on a Website that can include text, pictures, sound, and video.

30. Designing Web Pages • Professional Web page designers can produce a page for customers, or the customers can do it on their own using a menu-driven program included with a Web browser or a Web-page design software package such as Microsoft FrontPage or Adobe PageMill. • LAB WILL FOLLOW! 

31. Browsers – Software for connecting with websites • In computer science, a program that enables a computer to locate, download, and display documents containing text, sound, video, graphics, animation, and photographs located on computer networks.

32. URLs – Addresses for Web Pages • Uniform Resource Locator (URL) is a method of naming documents or places on the Websites. • A URL is a string of characters that identifies the type of document, the computer the document is on, the directories and subdirectories the document is in, and the name of the document.

33. A URL • http://www.nps.gov/abli/index.htm • Protocol : http • Domain name: www.nps.gov • Directory name: abli • File name: index.htm

34. Using Your Browser to Get Around the Web • Home page - the first page you see when you start up your browser • Getting around: • Back - takes you back to the previous page • Forward - takes you to a page you returned from • Home - takes you to your home page

35. Using Your Browser to Get Around the Web • History list - list accessible from browser’s toolbar that allows you to return to a page you have recently visited • Bookmarks or favorites - your favorite URLs stored in a list to permit frequent visits without retyping the URLs • Simultaneous viewing of two pages via File menu’s “New” item

36. Using Your Browser to Get Around the Web • Interactivity--hyperlinks, radio buttons, and fill-in text boxes • Radio buttons - little circles located in front of various options; selecting an option with the mouse places a dot in the corresponding circle Radio buttons and textbox

37. Web Portals: Starting Points for Finding Information • Web portal - website that groups together in one convenient location popular features such as search tools, e-mail, electronic commerce, and discussion groups

38. Web Portals: Starting Points for Finding Information • After logging on, you can: • Check the home page for general info • Use the directories to find a topic • Use keyword to search for a topic

39. Search Engine • Computer software that compiles lists of documents, on the World Wide Web (WWW), and the contents of those documents. Search engines respond to a user entry, or query, by searching the lists and displaying a list of documents that match the search query. Some search engines include the opening portion of the text of Web pages in their lists, but others include only the titles or addresses (URLS) of Web pages.

40. Four Types of Search Engines • Human-organized search sites • Computer-created search sites • Hybrid search sites • Metasearch sites

41. Human-organized search sites • Unlike indexes created by computers, humans can judge data for relevance and categorize them in ways that are useful to you.

42. Computer-created search sites • These are assembled by software "spiders" that crawl all over the Web and send back reports to be collected and organized with little human intervention. The downside is that computer-created indexes deliver you more information than you want.

43. Hybrid search sites • Hybrid sites generally use humans supplemented by computer indexes. The idea is to see that nothing falls through the cracks.

44. Metasearch sites • Metasearch sites send your query to several other different search tools and compile the results so as to present the broadest view.

45. Tips for Smart Searching • Start with general search tools. • Choose search terms well and watch spelling. • Use phrases with quotation marks rather than separate words • Put unique words first in a phrase • Use Boolean operators--AND, OR, NOT, and + and – signs--to make searching more precise • Read the Help or Search Tips section • Try an alternate general search site or a specific search site

46. Multimedia on the Web • Plug-ins • Applets • Text and Images • Animation • Video • Audio

47. Plug-ins • A program that adds a specific feature to a browser, allowing it to play or view certain files. Plug-ins are required by many Web sites if users want to fully experience the content.

48. Some Common Plug-ins

49. Applets • Small application programs that can be quickly downloaded and run by most browsers.

50. Text and Images • Most Web pages combine both text and images. • Animation • Animation is the rapid sequencing of still images to create the appearance of motion.