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The Internet and World Wide Web Ilona Kane The Internet A worldwide collection of networks that links millions of businesses, government agencies, educational institutions, and individuals. Internet’s Resources – Access to information and research – Communicate with others around the world – Bank, Shop, Download music and movies – Access other computers and exchange files History of the Internet Started by the Pentagon’s networking project known as the Advanced Research Projects Agency (ARPA) ARPA is an agency of the U.S. Department of Defense whose goal was to create a network that: ARPA underwent phenomenal growth as researchers realized the great benefit to sharing information In 1986, the National Science Foundation, (NSF) connected its huge network of five supercomputer centers, called NSFnet to ARPANET forming the complex networks and hosts known as the Internet today The Internet traffic today is handled by a variety of corporations and commercial firms, who along with telephone, cable, and satellite companies contribute to the internal structure of the internet. – Allowed scientists at different locations to share information and work together on military and scientific projects – Could function even if part of the network were disabled or destroyed by a disaster such as a nuclear attack This network is known as the ARPANET How the Internet Works Internet Service Providers – Is a business that has a permanent Internet connection and offers temporary connections to individuals and companies free or for a fee – 2 major types: Regional ISP- provides access to the Internet through one or more telephone numbers local to a specific geographic area National ISP- a larger business that provides local telephone numbers in major cities and towns nationwide Online Service provider- supplies Internet access, but has many members-only features that offer a variety of special content and services such as weather, games, and travel guides Wireless Service Provider- provides wireless Internet access to users with wireless modems or Web-enabled computer devices Connecting to the Internet 1. Dial-up access 1. 2. 3. 2. Digital Subscriber Line (DSL) 1. 3. Provides an easy and inexpensive way for users to connect to the Internet Uses a computer, a modem, and a regular telephone line to dial into an ISP or OSP Slow-speed technology Provides high-speed connections over a regular copper telephone line Cable Modem 1. 2. Provides high-speed Internet connections through the cable television network Along with DSL costs 2xs as much as dial-up How Data Travels the Internet Connection to the Internet is a transfer of data around the world using servers and clients Server- computer that manages the resources on a network and provides a central storage area for resources such as programs and data Client- a computer that can access the contents of the storage area on a server Internet Addresses IP Address- (Internet Protocol Address) is a number that uniquely identifies each computer or device connected to the Internet Domain name- the text version of an IP address DNS server- translates the domain name into its associated IP address, so data can route to the correct computer The World Wide Web Consists of a worldwide collection of electronic documents, also known as Web pages A collection of related Web pages- Web Site Browsing the Web Web browser- a software program that allows you to access and view Web pages – Most widely used: Microsoft Internet Explorer Netscape Home page- starting page for a browser – Provides information about the Web site’s purpose and content Hyperlink- (link) a built-in connection to another related Web page or part of a web page Uniform Resource Locator Is a Web page’s unique address – Tells the browser where to locate the document – Makes it possible for you to navigate using links Typical URL: http://www.lasalle.edu/students/home.htm – http = protcol – www.lasalle.edu = domain name – /students/home.htm = path Search Engines Is a software program you can use to find Web sites, Web pages, and Internet files – Are specifically useful when the exact URL is not known – Common Search Engines include: Dogpile, Excite, Yahoo, Google, Lycos Sources: dogpile.com, excite.com, yahoo.com, google.com, lycos.com Types of Web Pages 1. Portal Web Page- offers a variety of Internet services from a single convenient location 1. 2. 3. 4. 5. 6. Offer search engine News reports Weather Personalized web pages Email Chat rooms 2. News Web Page- contains news worthy material including stories and articles relating to current events, life, money, and sports More Web Pages 3. Informational Web Page- contains factual information such as census data, tax codes, published research findings 4. Business/Marketing Web Page- contains content that promotes or sells products or services – Such companies include: AT&T, and the Disney Co. 5. Advocacy Page- acts as a device to convince the reader of the validity of the content that describes a cause, opinion, or idea 6. Personal Web Page- established by a private individual who normally is not associated with any organization – To use for job hunting or to share life experiences Multimedia on the Web Any application that integrates texts with one or more of the following elements: graphics, sound, video, and virtual reality Graphics- a digital representation of information such as a drawing, chart, or photograph Animation- the appearance of motion created by displaying a series of still images in a rapid sequence – Makes pages more visually interesting and draws attention Audio- music, speech, or any other sounds – MP3 is a popular technology that compresses audio – Streaming- the process of transferring data in a continuous and even flow Important because most users do not have a fast enough Internet connection More Multimedia • Video- images that are played back at various speeds – Consist of individual video files, such as movies or TV clips, that you download – Web cam- a video camera whose output displays on a Web page • Virtual Reality- the use of computers to simulate a real or imagined environment that appears as a 3D space – Often used for scientific models, architectural layouts, and games Webcasting Pull Technology Push Technology 1. a server automatically downloads content to your information which relies computer at regular intervals on a client such as your or whenever updates are computer to request a Web made to the site page from a server 2. Example: current sporting 2. Example: enter a URL or event scores displayed on click a link your desktop 1. Method of obtaining Webcasting – uses pull technology, push technology and/or streaming media to deliver information at regualr intervals without you having to request it, or to deliver live recorded sound and video broadcast to your computer Creating a Web Site Web page authorizing – Involves working on the computer to compose the Web site 1. 2. Word processing packages help create basic web pages that contain text and graphics Web page authorizing software Is specifically to help create a web page Used to create more sophisticated web pages that include animation, video, and sound 3. When using a word processing or Web page authorizing software, the Web page is saved in Hypertext Markup Language (HTML) Is a set of special codes that format a file for use on a web page Deploying and Maintaining a Web Site Store a created Web page on a Web server – Many ISPs and OSPs provide their customers with a Web address and storage space for the Web site – Web hosting Services- provide storage for your Web site for a monthly fee Upload the Web site- copy it from your computer to the Web server Submission Service- a Web-based business that offers a registration package in which you pay to register with hundreds of search engines Webmaster- the individual responsible for maintaining a Web site and developing Web pages E-mail The transmission of messages and files via a computer network One of the original services of the Internet Email address- combination of user name and domain name that identifies a user Address Book- program in email that a contains a list of names and email addresses Mailbox- a storage location usually residing on the computer that connects you to the Internet Web-based Groups Message Board- type of discussion group, also known as a discussion board Mailing Lists- a group of e-mail names and addresses Chat rooms- a location on the Internet server that allows a real-time conversation to take place on a computer Instant Messaging- a real-time Internet communications service that notifies you when one or more people are online and allows you to exchange messages or files Sources Discovering Computers 2003 Web sites– Aol.com – Dogpile.com – Excite.com – Google.com – Lycos.com – Msn.com – Yahoo.com