The Internet & the World Wide Web

2.1 Connecting to the Internet • Internet History • Began with 1969’s ARPANET for US Dept. of Defense • 62 computers in 1974 • 500 computers in 1983 • 28,000 computers in 1987 • Early 1990s, multimedia became available on internet • To connect you need • An access device (computer with modem) • A means of connection (phone line, cable hookup, or wireless) • An internet access provider © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.1 Connecting to the Internet Definition: Bandwidth is an expression of how much data – text, voice, video and so on – can be sent through a communications channel in a given amount of time. Definition: Baseband is a slow type of connection that allows only one signal to be transmitted at a time. Definition: Broadband is a high speed connection that allows several signals to be transmitted at once. © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.1 Connecting to the Internet • Physical connection to internet—wired or wireless • Telephone [dial-up] modem • High-speed phone line—ISDN, DSL, T1 • Cable modem • Wireless—satellite and other through-the-air links © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.1 Connecting to the Internet • Data Transmission Speeds • Originally measured in bits per second (bps) • 8 bits are needed to send one character, such as A or a • Kbps connections send a thousand bits per second • Mbps connections send 1 million bits per second • Gbps connections send 1 billion bits per second • Uploading & Downloading • Upload—transmit data from local to remote computer • Download—transmit data from remote to local computer © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.1 Connecting to the Internet • Narrowband (Dial-Up Modem) • Telephone line narrowband, or low bandwidth, low speed • Dial-up connection—use of telephone modem to connect to internet • Telephone Modems • Can be either internal or external • Most ISPs offer local access numbers • Need call waiting turned off; either manually or in Windows © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.1 Connecting to the Internet • High-Speed Phone Lines • ISDN line • Allows voice, video, & data transmission over copper phone lines • Can transmit 64 to 128 Kbps • DSL line • Uses regular phone lines, DSL modem • Receives data at 1.5-10 Mbps; sends at 128Kbps – 1.5 Mbps • Need to live within 3.3 miles of phone company switching office • T1 line—very expensive • Traditional trunk line; carries 24 normal telephone circuits • Transmission rate of 1.5 to 6 Mbps • Cable modem • TV cable system with internet connection • Receives data at up to 30 Mbps; sends at 1.4 Mbps © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.1 Connecting to the Internet • How long to Download a 6-Minute Video? • 28.8 Kbps telephone—4 ¾ hours • ISDN line—1hour • DSL line—11 minutes • Cable modem—2 minutes • T1 line--instantaneously © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.1 Connecting to the Internet • Satellite Wireless Connection • Transmits data between satellite dish and satellite orbiting earth • Sends data at around 512 Kbps; receives at 1.5 Mbps • Connection is always on • Requires internet access provider with 2-way satellite transmission © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.1 Connecting to the Internet • Other Wireless Connections: Wi-Fi & 3G • Wi-Fi—stands for “wireless fidelity” • Name for a set of wireless standards (802.11) set by IEEE • Transmits data wirelessly for 300 – 500 feet from access point (hotspot) • Typically used with laptops that have Wi-Fi hardware • 3G—stands for “third generation” • High-speed wireless that does not need access points • Used in PDAs and smartphones • Can deliver downloadable video clips, hi-res games © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.1 Connecting to the Internet • Internet Access Providers—Three Types • Internet Service Provider (ISP)—e.g., Earthlink • Company that links online users to its servers, which link users to the internet through another company’s network • Commercial Online Service—e.g., AOL • Members-only company that provides specialized content as well as internet access • Wireless Internet Service Provider (WISP)—e.g., Cingular, Sprint • Enables wireless laptop and smartphone users to access internet © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.2 How Does the Internet Work? • The internet consists of thousands of smaller networks • Central to this arrangement are Client/Server networks • Client: a computer requesting data or services • Server or host computer: a central computer supplying data or services requested of it © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.2 How Does the Internet Work? • Internet Connection: POP, NAPs, Backbone, & Internet2 • Point of Presence (POP) • A collection of modems and other equipment in a local area • A local gateway to the ISP’s network • ISP connects to a network access point • Network Access Point (NAP) • A routing computer at a point on the internet where several connections come together • NAPs are owned by network service providers (e.g., MCI) • PNAPs provide more efficient routing of data [continued] © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.2 How Does the Internet Work? • Internet Backbone • High-speed, high-capacity data transmission lines • Uses the newest technology • Providers include AT&T, Sprint, Verizon, GTE, Teleglobe, and Deutsche Telekom • Internet 2 • Cooperative university/business research project • Adds new “toll lanes” to older internet to speed things up • Advances videoconferencing, research, collaboration © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.2 How Does the Internet Work? • Handshaking & Authentication: Connecting Your Modem to ISP • Handshaking—fastest transmission speed established • Authentication—correct password & user name • Protocols • The set of rules a computer follows to electronically transmit data. • TCP/IP is the internet protocol • Developed in 1978 • Used for all internet transactions • Packets • Fixed-length blocks of data for transmission • Data transmissions are broken up into packets © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.2 How Does the Internet Work? • IP Addresses • Every device connected to the internet has an address • Each IP address uniquely identifies that device • The address is four sets of numbers separated by periods • Each number is between 0 and 255 • Example: 95.160.10.240 • Dynamic IP addresses change with every use • Static IP addresses don’t change © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.2 How Does the Internet Work? • Who runs the internet? • The board of trustees of the Internet Society (ISOC) oversees the standards • Internet Corporation for Assigned Names and Numbers (ICANN) regulates domain names © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.3 The World Wide Web Discussion Question: What type of internet browser do you think is the best? Have you used others? • Browsers • Software for web-surfing • Examples: Internet Explorer, Mozilla FireFox, Apple Macintosh’s Safari, Google’s Chrome, Microsoft’s Bing • Website • The location on a particular computer that has a unique address • Example: www.barnesandnoble.com, www.mcgraw-hill.com • The website could be anywhere--not necessarily at company headquarters © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.3 The World Wide Web • Web Page • A document on the web that can include text, pictures, sound, and video • The first page on a website in the Home page • The Home page contains links to other pages on the website © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.3 The World Wide Web • Uniform Resource Locator (URL) • A character string that points to a specific piece of information anywhere on the web • A website’s unique address • It consists of • The web protocol, http • The domain name of the web server • The directory name or folder on that server • The file within the directory, including optional extension © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.3 The World Wide Web • TCP/IP—Internet Protocol • HTTP—Protocol Used to Access World Wide Web • Hypertext Markup Language (HTML) • The language used in writing and publishing web pages • Set of instructions used to specify document structure, formatting, and links to other documents on the web • Hypertext links connect one web document to another © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.3 The World Wide Web • Web Browsers • Your tool for using the internet • Comes preinstalled on most PCs • 5 basic elements • Menu bar • Toolbar • URL bar • Workspace • Status bar © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.3 The World Wide Web • Home Page • The page you see when you open your web browser • You can change the Home Page on your browser • Back, Forward, Home & Search • Use the menu bar icons to move from one page to another © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.3 The World Wide Web • Navigation • History Lists • A list of websites you visited since you opened up your browser for this session • Allows you to easily return to a particular site © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.3 The World Wide Web • Navigation • Bookmarks • Allows you to store the URL from a site on your computer so you can find it again in another browser session • To save the URL for a site, click on “Favorites” in Internet Explorer or “Bookmarks” Mozilla Firefox © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.3 The World Wide Web • Navigation—Three Ways to Interact with Any Given Web Page • Use mouse to click on hyperlink, which will transfer you to that page • Radio buttons: little circles located in front of various options • Search box: used for entering text in a fill-in text box, then hitting enter © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.3 The World Wide Web • Navigation • Scroll arrows: small up/down and left/right arrows that when clicked on, move the screen so that you can see the rest of the web page • Frame: an independently controllable section of a web page © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.3 The World Wide Web • Web portals • A gateway website that offers a broad array of resources and services, online shopping malls, email support, community forums, stock quotes, travel info, and links to other categories • Examples: Yahoo!, Google, Bing, Lycos, and AOL • Most require you to log in, so you can • Check the Home page for general information • Use the subject guide to find a topic you want • Use a keyword to search for a topic © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.3 The World Wide Web • Search Services & Search Engines • Organizations that maintain databases accessible through websites to help you find information on the internet • Examples: portals like Yahoo!, and Bing, plus Google, Ask.com, Gigablast • Search services maintain search engines—programs that users can use to ask questions or use keywords to find information • Databases of search engines are compiled using software programs called spiders • Spiders crawl through the World Wide Web • Follow links from one page to another • Index the words on that site © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.3 The World Wide Web Discussion Question: Do you prefer one search engine for finding information? Why? • Search Services & Search Engines • A search by a single search engine never covers the entire web • Search engines differ in what they cover © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.3 The World Wide Web • 4 Web Search Tools • Individual Search Engines • Compile their own searchable database on the web • You search by typing keywords and receiving “hits” • Examples are Ask, Bing, Google, and Yahoo! • Subject Directories • Created and maintained by human editors, not electronic spiders • Allow you to search for information by selecting lists of categories or topics • Example sites are Beaucoup!, Galaxy, Google Directory, LookSmart, Open Directory Project, and Yahoo! Directory © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.3 The World Wide Web • 4 Web Search Tools • Metasearch Engines • Allows you to search several search engines simultaneously • Examples are Clusty, Dogpile, Grokker, Mamma, MetaCrawler, and Webcrawler • Specialized Search Engines • Help locate specialized subject matter, such as info on movies, health, jobs • Examples are Career.com. WebMD, Expedia © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.3 The World Wide Web • Smart Searching: Three General Strategies • If you’re just browsing . . . • Try a subject directory • Next try a metasearch engine • If you’re looking for specific information . . . • Try a Answers.com “one-click” search • Or go to a general search engine, then a specialized one • If you’re looking for everything on a subject . . . • Try the same search on several search engines © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.3 The World Wide Web • Multimedia Search Tools • Still images—e.g., Google Image Search • Audio—e.g., Yahoo! Audio Search • Video—e.g., AllTheWeb • Multiple sources, including music—e.g., A9, Rocket Music Song ID (cellphones) • Scholarly—e.g., Google Scholar © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.3 The World Wide Web • Desktop Search • Desktop search engine: a tool that extends searching beyond the web to the contents of your computer’s hard disk • Uses technology similar to that in web search engines • Offered by all of the principal search engine services as a download © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.3 The World Wide Web • Tagging • Tags: do-it-yourself labels that people can put on anything found on the internet, from articles to photos to videos • Can be shared easily with other people • Tags are available through del.icio.us, BlinkList, Flickr © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.4 Email & Other Ways of Communicating over the Net Discussion Question: If your email is stored at the server and servers are backed up, when you delete an email is it gone for good? • Email Program • Enables you to send email by running email software on your computer that interacts with an email server at your internet access provider • Incoming mail is stored on the server in an electronic mailbox • Upon access, mail is sent to your software’s inbox • Examples: Windows Mail (Outlook), Apple Mail © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.4 Email & Other Ways of Communicating over the Net • Web-Based Email • You send and receive messages by interacting via a browser with a website • Advantage: You can easily send and receive messages while traveling • Examples: Yahoo! Mail, Windows Live Hotmail, Gmail (Google), and AOL Mail © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.4 Email & Other Ways of Communicating over the Net • Tips for Using Email 1. Type addresses carefully, including capitalization, underscores, and periods • Use the reply command to avoid addressing mistakes • Use the address-book feature to store email addresses • Deal with each email only once • Don’t “bloat” you email To keep email, use filters (Instant organizer folders) © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.4 Email & Other Ways of Communicating over the Net • Email Attachments • A copy of a file or document that you send attached to an email to one or more people • The recipient must have compatible software to open the attachment. If they don’t have Excel, they probably can’t read the spreadsheet you sent them. Be careful about opening attachments • Many viruses hide in them • Know who is sending it to you before you open it © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.4 Email & Other Ways of Communicating over the Net • Instant Messaging • Any user on a given email system can send a message and have it pop up instantly on the screen of anyone logged into that system • To get IM: download IM software from a supplier • Examples: AOL/AIM, Google Talk, MySpace, Facebook, and Yahoo! Messenger • The downside of IM: • Lack of privacy • Lack of common standards • Time wasters © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.4 Email & Other Ways of Communicating over the Net • FTP – File Transfer Protocol • A software standard for transferring files between computers, including those with different operating systems • You can transfer files from an FTP site on the internet to your PC • FTP sites offer many free files • FTP sites may be either public or proprietary • You can download using your web browser or FTP client programs © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.4 Email & Other Ways of Communicating over the Net • Newsgroups • A giant electronic discussion board • There are thousands of free internet newsgroups • Usenet is the worldwide public network of servers on the internet www.usenet.com • To participate you need a newsreader • Listserv • An email-based discussion group • Uses an automatic mailing-list server that sends email to subscribers on selected topics © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.4 Email & Other Ways of Communicating over the Net • Real-Time Chat (RTC) • Participants have a typed discussion while online at the same time • RTC involves message board, with many contributions (“posts”) • To start, user service on your browser, such as IRC • IM is one-on-one, but RTC has a list of participants © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

2.4 Email & Other Ways of Communicating over the Net • Netiquette – Appropriate Online Behavior • Before you ask a question, consult the FAQs • Avoid flaming • Don’t SHOUT – use all capital letters • Be careful with jokes • Avoid sloppiness, but avoid criticizing other’s sloppiness • Don’t send huge file attachments unless requested • When replying, quote only the relevant portion • Don’t “overforward” © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

The Internet & the World Wide Web