Monday, May 30, 2011

The Internet and World Wide Web

0 comments

Chapter 2: The Internet and World Wide Web




This chapter introduces one of the most significant innovations of the past half century – the Internet. The Internet is defined, and the history of the Internet is detailed. You discover how the Internet works and learn about Internet service providers and online services, connecting to the Internet, how data travels the Internet, and Internet addresses. The World Wide Web, search engines, and multimedia on the Web are explained. You become familiar with Webcasting, electronic commerce, Web publishing, and other Internet services including e-mail, FTP, Telnet, newsgroups, mailing lists, chat rooms, and instant messaging. Finally, netiquette, the Internet code of acceptable behavior by users, is described.
      Discuss How The Internet Works
The Internet is a worldwide collection of networks that links millions of businesses, government offices, educational institutions, and individuals. Data is transferred over the Internet using servers, which are computers that manage network resources and provide centralized storage areas, and clients, which are computers that can access the contents of the storage areas. The data travels over communications lines. Each computer or device on a communications line has a numeric address called an IP (Internet protocol) address, the text version of which is called a domain name. Every time you specify a domain name, a DNS (domain name system) server translates the domain name into its associated IP address, so data can route to the correct computer.
You can access the Internet through an Internet service provider, an online service provider, or a wireless service provider. An Internet service provider (ISP) provides temporary Internet connections to individuals and companies. An online service provider (OSP) also supplies Internet access, in addition to a variety of special content and services. A wireless service provider (WSP) provides wireless Internet access to users with wireless modems or Web-enabled handheld computers or devices.
Employees and students often connect to the Internet through a business or school network that connects to a service provider. For home or small business users, dial-up access provides an easy and inexpensive way to connect to the Internet. With dial-up access, you use a computer, a modem, and a regular telephone line to dial into an ISP or OSP. Some home and small business users opt for newer, high-speed technologies. DSL (digital subscriber line) provides high-speed connections over a regular copper telephone line. A cable modem provides high-speed Internet connections through a cable television network.
     Identify A URL
The most widely used service on the Internet is the World Wide Web. The World Wide Web (WWW or Web) consists of a worldwide collection of electronic documents called Web pages. A browser is a software program used to access and view Web pages. Each Web page has a unique address, called a URL(Uniform Resource Locator), that tells a browser where to locate the Web page. A URL consists of a protocol, domain name, and sometimes the path to a specific Web page or location on a Web page. Most URLs begin with http://, which stands for hypertext transfer protocol, the communications standard that enables pages to transfer on the Web.
search engine is a software program you can use to find Web sites, Web pages, and Internet files. To find a Web page or pages, you enter a relevant word or phrase, called search text or keywords, in the search engine’s text box. Many search engines then use a program called a spider to read pages on Web sites and create a list of pages that contain the keywords. Any Web page that is listed as the result of the search is called a hit. Each hit is a link that can be clicked to display the associated Web site or Web page.
There are six basic types of Web pages. An advocacy Web page contains content that describes a cause, opinion, or idea. A business/marketing Web pagecontains content that promotes or sells products or services. An informational Web page contains factual information. A news Web page contains newsworthy material including stories and articles relating to current events, life, money, sports, and the weather. A portal Web page offers a variety of Internet services from a single, convenient location. A personal Web page is maintained by a private individual who normally is not associated with any organization.
Many exciting Web pages use multimedia. Multimedia refers to any application that integrates text with one of the following elements: graphics, sound, video, virtual reality, or other media elements.
graphic is a digital representation of information such as a drawing, chart, or photograph. Two common file formats for graphical images on the Web are JPEG(Joint Photographic Experts Group) and GIF (Graphics Interchange Format), which use compression techniques to reduce the size of graphics files and thus speed downloading.
Animation is the appearance of motion created by displaying a series of still images in rapid sequence. One popular type of animation, called an animated GIF, uses computer animation and graphics software to combine several images into a single GIF file.
Audio is music, speech, or any other sound. A common format for audio files on the Web is MP3, a popular technology that compresses audio. More advanced Web audio applications use streaming audio, which transfers audio data in a continuous and even flow, allowing users to listen to the sound as it downloads. Videoconsists of full-motion images that are played back at various speeds. Video files often are quite large in size. The Moving Pictures Experts Group (MPEG) defines a popular video compression standard. Streaming video allows you to view longer or live video images as they are downloaded.
Virtual reality (VR) is the use of computers to simulate a real or imagined environment that appears as a three-dimensional (3-D) space. A VR world is an entire 3-D site that contains infinite space and depth.
      Define Webcasting
Pull technology is a method of obtaining information that relies on a client such as your computer to request a Web page from a server. On the other hand,Webcasting, also called push technology, is a method of obtaining information in which a server automatically downloads content to your computer at regular intervals or whenever updates are made to the site. Webcasting saves time by delivering information at regular intervals and allows users to view Web content when they are offline, that is, when they are not connected to the Internet.
      Describe The Uses Of Electronic Commerce (E-Commerce)
Electronic commerce (e-commerce) is a financial business transaction that occurs over an electronic network such as the Internet. Today, there are three types of e-commerce. Business to consumer (B-to-B or B2Ce-commerce consists of the sale of goods to the general public. Customers visit an online business through an electronic storefront, which contains descriptions, graphics, and a shopping cart that allows customers to collect their purchases. Consumer to consumer (C-to-C or C2Ce-commerce occurs when one consumer sells directly to another. An online auction is an example of consumer to consumer e-commerce. Business to business (B-to-B or B2Be-commerce, which is the most prevalent type of e-commerce, takes place between businesses, with businesses typically providing services to other businesses.
    Explain How E-Mail, FTP, Newsgroups And Message Boards, Mailing Lists, Chat Rooms, And Instant Messaging Work
A variety of services are used widely on the Internet, including e-mail, FTP, newsgroups and message boards, mailing lists, chat rooms, and instant messaging. E-mail (electronic mail) is the transmission of messages and files via a computer network. You use an e-mail program to create, send, receive, forward, store, print, and delete messages. To receive messages, you need an e-mail address, which is a combination of a username and a domain name that identifies a user.
FTP (File Transfer Protocol) is an Internet standard that allows you to upload and download files with other computers on the Internet. An FTP server is a computer that allows you to use FTP to upload files to, and download files from, an FTP site. With anonymous FTP, anyone can transfer some, if not all, available files. A newsgroup is an online area in which users conduct written discussions about a particular subject. The computer that stores and distributes newsgroup messages is called a news server. You use a program called a newsreader to access a newsgroup, read previously entered messages (called articles), and add (post) messages of your own.
thread consists of the original article and all subsequent related replies. In a moderated newsgroup, a moderator reviews articles and posts them, if appropriate. A message board is a popular Web-based type of discussion group that does not require a newsreader and typically is easier to use than a newsgroup. A mailing list is a group of e-mail names and addresses given a single name. To add your e-mail name and address to a mailing list you subscribe to it; to remove your name, you unsubscribe.
chat is real-time (meaning everyone involved in the chat is online at the same time) typed conversation that takes place on a computer. A location on an Internet server that permits users to chat is called a chat room. Some chat rooms support voice chats and video chats, where you can hear or see others and they can hear or see you as you chat. A chat client is a program on your computer that allows you to connect to a chat server and start a chat session. Instant messaging (IM) is a real-time Internet communications service that notifies you when one or more people are online and then allows you to exchange messages or join a private chat room.
Netiquette, which is short for Internet etiquette, is the code of acceptable behaviors users should follow while on the Internet. Rules for e-mail, newsgroups, and chat rooms include:
  • Keep messages brief and use proper grammar and spelling.
  • Be careful when using sarcasm and humor.
  • Be polite and avoid offensive language.
  • Avoid sending flames (abusive messages) and spam (unsolicited junk mail).
  • Do not use all capital letters, which is the equivalent of SHOUTING!
  • Use emoticons (such as :) for smile) to express emotion.
  • Use abbreviations (such as BTW for by the way) for popular phrases.
  • Clearly identify a spoiler, which is a message that reveals a solution to a game or an ending to a movie or program.
  • Read the FAQ (frequently asked questions) document.
  • Do not assume all material is accurate or up-to-date.
  • Never read someone’s private e-mail.

0 comments:

Post a Comment