The World Wide Web

Although many people use the terms World Wide Web and Internet interchangeably, the World Wide Web actually is a service of the Internet. While the Internet was developed in the late 1960s, the World Wide Web emerged in the early 1990s. Since then, it has grown phenomenally to become one of the more widely used Internet services.

 The World Wide Web emerged in the early 1990s. Since then, it has grown phenomenally to become one of the more widely used Internet services.

 The World Wide Web (WWW), or Web, consist of a worldwide collection of electronic documents. Each electronic document on the Web is called a Web page, which can contain text, graphics, animation, audio, and video. Additionally, Web pages usually have built-in connections to other documents. Some Web pages are static (fixed); others are dynamic (changing). Visitors to a static Web page all see the same content. With a dynamic Web page, by contrast, visitors can customize some or all of the viewed content such as desired stock quotes, weather for a region, or ticket availability for flights.

A Web site is a collection of related Web pages and associated items, such as documents and pictures, stored on a Web server. A Web server is a computer that delivers requested Web pages to your computer. The same Web server can store multiple Web sites. Some industry experts use term Web 2.0 to refer to web sites that provide a means for users to share personal information (such as social networking Web sites), allow users to modify Web site content (such as wikis, which are discussed later in this chapter), and have application software built into the site for visitors to use (such e-mail and word processing programs).

Browsing the Web

 A Web browser, or browser, is application software that allows users to access and view Web pages access and view Web pages or access Web 2.0 programs. To browse the Web, you need a computer or mobile device that is connected to the Internet and has a Web browser. The more widely used Web browsers for personal computers are Internet Explorer, Firefox, Opera, Safari, and Google Chrome.

 With an Internet connection established, you start a Web browser. The browser retrieves and displays a starting Web page, sometimes called the browser's home page. The initial home page that is displayed is one selected by your Web browser. You can change your browser's home page at anytime.

 Another use of the term, home page, refers to the first page that a Web site displays. Similar to a book cover or table of contents for Web site, the home page provides information about the Web site's purpose and content. Many Web sites such as iGoogle, allow you to personalize the home page so that it contains areas of interest to you. The home page usually contains links to other documents, Web pages, or Web sites. A link, short for hyperlink, is a built-in connection to another related Web page or part of a Web page.

 Internet-enabled mobile devices such as smart phones use a special type of browser, called a phones use a special type of browser, called a microbrowser, which is designed for their small screens and limited computing power. Many web sites design Web pages specifically for display on a microbrowser.

 For a computer or mobile device to display a Web page, the page must be downloaded. Downloading is the process of a computer or device receiving information, such as a Web page, from a server on the Internet. While a browser downloads a Web page, it typically displays an animated logo or icon in the browser window. The animation stops when the download a Web page varies depending on the speed of your Internet connection and the amount of graphics involved.

Web Addresses

 A web page has a unique address, called a URL (Uniform Resource Locator) or Web address. For example, the home page for the United States National Park Service Web site has http://www.nps.gov/grsm/planyourvisit/wildlifeviewing.htm in the Address bar and then press the  ENTER key, the browser downloads and displays the Web page.

 A Web address consists of a protocol, domain name, and sometimes the path to a specific Web page or location on a Web page. Many Web page addresses begin with http://. The http, which stands for Hypertext Transfer Protocol, is a set of rules that defines how pages transfer on the Internet.

 To help minimize errors, many browsers and Web sites do not require you enter the http:// and www portions of the Web address in the Address bar. If you enter an incorrect Web address, the browser may display a list of similar address or related Web sites from which you can select.

 When you enter the Web address, http://www.nps.gov/grsm/planyourvisit/wildlifeview.htm in the web browser, it sends a request to the Web server that contains the nps.gov Web site. The server then retrieves the Web page named wildlifeviewing.htm that is located in the grsm/planyourvisit path and delivers it to your browser, which then displays the Web page on the screen.

 To save time, many users create bookmarks for their frequently visited Web pages. A bookmark, or favorite, is a saved Web address that you access by clicking its name in a list. That is, instead of entering a Web address to display a Web page, you can click a previously saved bookmark.

 When you enter a Web address in a browser, you request, or pull, information from a Web server. Some Web servers also can push content to your computer at regular intervals or whenever updates are made to the site. For example, some Web servers provide the capability of displaying current sporting event scores or weather reports on your computer screen.

Navigating Web Pages

 Most Web pages contain hypertext or hypermedia links. Hypertext refers to links in text-based documents, whereas hypermedia combines text-based links with graphic, audio, and video links. Links allow you to obtain information in a nonlinear way. That is, instead of accessing topics in a specified order, you move directly to a topic of interest. Branching from one related topic to another in a nonlinear fashion is what makes links so powerful. Some people use the phrase, surfing the Web, to refer to the activity of using links to explore the web, to refer to the activity of using links to explore the Web.

 A link can be text or an image. Text links may be underlined and/or displayed in a color different from other text on the Web page. Pointing to, or positioning the pointer on, a link on the screen typically changes the shape of the pointer to a small hand with a pointing index finger. Pointing to a link also sometimes causes the link to change in appearance or play a sound. For example, an underline may disappear, the text may change color, the image may change, etc.

 Each link on a Web page corresponds to a Web address or a document. To activate a link, you click it, that is, point to the link  and then press the left mouse button. Clicking a link causes the Web page or document associated with the linked object might be on the same Web page, a different Web page at the same Web site, or a separate Web page at a different Web site in another city or country. To remind you visually that you have clicked a link, a text link often changes color after you click it.

 Most current Web browsers support tabbed browsing, where the top of the browser displays a tab (similar to a file folder tab) for each Web page you open. To move from one open Web to another, you click the tab in the Web browser. Tabbed browsing allows users to have multiple home pages that automatically open when the browser starts. You also can organize tabs in group, called a tab group, and save the group as a favorite, so that at any time you can display all tabs at once.
 Because some Web sites attempt to track your browsing habits or gather personal information, some current Web browsers include a feature that allows you to disable and/or more tightly control the dissemination of your browsing habits and personal information.

Searching the Web

 The Web is a worldwide resource of information. A primary reason that people use the Web is to search for specific information, including text, pictures, music, and video.

 The first step in successful searching is to identify the main idea or concept in the topic about which you are seeking information. Determine any synonyms, alternate spellings, or variant word forms for the topic. Then, use a search tool to locate the information.

 Two types of search tools are search engines and subject directories. A search engine is a program that finds Web sites, Web pages, images, videos, news, maps, and other information related to a specific topic. A subject directory classifies Web pages in an organized set of categories, such as sports or shopping, and related subcategories.

 Some Web sites offer the functionality of both a search engine and a subject directory.

Search Engines  A search engine is helpful in locating information for which you do not know an exact Web address or are not seeking a particular Web site. Thousands of search engines are available. Some search through Web pages for all types of information. Other search engines can restrict their searches to a specific type of information, such as the following items:

• Images – pictures, diagrams, and drawings.
• Video – home videos, music videos, television programs, and movie clips.
• Audio – music, song, recordings, and sounds.
• Publications – news articles, journals, and books.
• Maps – maps of a business or address, or driving directions to a destination.
• People or Businesses – addresses and telephone numbers.
• Blogs – specific opinions and ideas for others.

 Search engines require that you enter a word or phrase, called search text or search query, that describes the item you want to find. Each word in the search text can be broad, such as spring break destinations, or more specific, such as Walt Disney World. Search engines often respond with thousands of results, whose content varies depending on the type of information you are seeking. Some results are links to Web pages or articles; other results are media, such as images and videos. You may find that many items that appear in the search results have little or nor bearing on the item you are seeking. You can eliminate the superfluous items in your search results by carefully crafting search text that limits the search.

 If you misspell search text, many search engines identify alternative search text. Some also provide suggested keywords, links, and/or images as you begin typing your search text. The results of a search text, called hits, include many links to Web pages that reference the search. Each hit in the list has a link that, when clicked, displays an associated Web site or Web page. Most search engines sequence the hits based on how close the words in the search text are to one another in the titles and descriptions of the hits. Thus, the first few links probably contain more relevant information.

 Some Web browsers contain an Instant Search box that, when filled in, uses a predefined or default search engine to perform searches. Using the Instant Search box eliminates the steps of displaying the search engine's Web page prior to entering the search text.

 If you enter a phrase with spaces between the words in the search text, most search engines display results (hits) that include all of the words, except for common words (e.g., to, the, and). You can include some operators (e.g., +, -, *, OR, “”) in your search text to refine your search. Instead of using operators to refine your search text, many search engines have an Advanced Search feature that displays a form that assists with refining your search.

 Other techniques you can use to improve your search include the following:

• Use specific nouns.
• Put the most important terms first in the search text.
• List all possible spellings, for example, email, e-mail.
• Before using a search engine, read its Help information.
• If the search is unsuccessful with one search engine, try another.

  Some search engines that work with navigation devices are location based, meaning they display results related to the device's current geographical position. For example, your mobile device can display all gas stations within a certain distance of your current location.

  Many search engines use a program called a spider to build and maintain a lists of words found on Web sites. When you enter search text, the search engine scans this prebuilt list for hits. The more sophisticated the search engine combined with precise search criteria, the more rapid the response and effective the search.

Subject Directories  A subject directory provides categorized lists of links arranged by subject. Using the search tool, you locate a particular topic by clicking links through different levels, moving from the general to the specific. Each time you click a category link, the subject directory displays a list of subcategory links, from which you again choose. You continue in this fashion until the search tool displays a list of Web pages about the desired topic.

 The major disadvantage with the subject directory is that users have difficulty deciding which categories to choose as they work through the menus of links presented.

Types of Web Sites

Thirteen types of Web sites are portal, news, informational, business/marketing, blog, wiki, online social network, educational, entertainment, advocacy, Web application, content aggregator, and personal. Many Web sites fall in more than one of these categories.

Portal  A portal is a Web site that, offers a variety of Internet services from a single, convenient location. Most portals offer these free services: search engine; news; sports and weather; Web publishing; reference tools such as yellow pages, stock quotes, and maps; shopping; and e-mail and other communications services.

 Many portals have online communities. An online community is a Web site that joins a specific group of people with similar interests or relationships. These communities may offer online photo albums, chat rooms, and other services to facilitate communications among members.

  Popular portals include AltaVista, AOL, Excite, GO.com, iGoogle, Lycos, MSN, and Yahoo!. A wireless portal is a portal designed for Internet-enabled mobile devices.

News  A news Web site contains newsworthy material including stories and articles relating to current events, life, money, sports, and the weather. Many magazines and newspapers sponsor Web sites that provide summaries of printed articles, as well as articles not included in the printed versions. Newspapers and television and radio stations are some of the media that maintain news Web sites.

Informational  An informational Web site contains factual information. Many United States government agencies have informational Web sites providing information such as census data, tax codes, and the congressional budget. Other organizations provide information such as public transportation schedules and published research findings.

Business/Marketing  A business/marketing Web site contains content that promotes or sells products or services. Nearly every enterprise has a business/marketing Web site. Allstate Insurance Company, Dell Inc., General Motors Corporation, Kraft Foods Inc., and Walt Disney Company all have business/marketing Web sites. Many of these enterprises also allow you to purchase their products or services online.

Blog  A blog, short for Weblog, is an informal Web site consisting of time-stamped articles, or posts, in a diary or journal format, usually listed in reverse chronological order. A blog that contains video clips is called a video blog, or vlog. A microblog allows users to publish short messages, usually between 100 and 200 characters, for others to read. Twitter is a popular microblog. The term blogosphere refers to the world wide collection of blogs, and the vlogosphere refers to all vlogs worldwide.

 Blogs reflects the interests, opinions, and personalities of the author, called the blogger or vlogger (for vlog author), and sometimes site visitors.

  Blog have become an important means of worldwide communications. Businesses create blogs to communicate with employees, customers, and vendors. Teachers create blogs to collaborate with other teachers and students. Home users create blogs to share aspects of their personal life with family, friends, and others.

Wiki  A wiki is a collaborative Web site that allows users to create, add to, modify, or delete the Web site content via their Web browser. Many wikis are open to modification by general public. Wikis usually collect recent edits on a Web page so that someone can review them for accuracy. The difference between a wiki and a blog is that users cannot modify original posts made by the blogger. A popular wiki is Wikipedia, a free Web encyclopedia.

Online Social Network  An online social network, also called a social network Web site, is a Web site that encourages members in its online community to share their interest, ideas, stories, photos, musics, and videos with others registered users. Most include chat rooms, newsgroups, and other communications services. Popular social networking Web sites include MySpace and Facebook, with Facebook alone boasting more than 300 million active users. In some social networking Web sites, such as Second Life, users assume in a role-playing type of environment.

 A media sharing Web site is a specific type of online social network that enables members to share media such as photos, musics, and videos. Flickr, Fotki, and Webshots are popular photo sharing communities; PixelFish and YouTube are popular video sharing communities.

Educational  An educational Web site offers exciting, challenging avenues for formal and informal teaching and learning. On the Web, you can learn how airplanes fly or how to cook a meal. For a more structured learning experience, companies provide online training to employees; and colleges offer online classes and degrees. Instructors often use the Web to enhance classroom teaching by publishing course materials, grades, and other pertinent class information.

Entertainment  An entertainment Web site offers an interactive and engaging environment. Popular entertainment Web sites offer music, videos, sports, games, ongoing Web episodes, sweepstakes, chat rooms, and more.

Sophisticated entertainment Web sites often partner with other technologies. For example, you can cast your vote about a topic on a television show.

Advocacy  An advocacy Web site contains content that describes a cause, opinion, or idea. These Web sites usually present views of a particular group or association. Sponsors of advocacy Web sites include the Democratic National Committee, the Republican National Committee, the Society fro the Prevention of Cruelty to Animals, and the Society to Protect Human Rights.

Web Application  A Web application, or Web app, is a Web site that allows users to access and interact with software through a Web browser on any computer or device that is connected to the Internet. Some Web applications provide free access to their software. Others offer part of their software free and charge for access to more comprehensive features or when a particular action is requested. Example of Web application include Google Doc (word processing, spreadsheet, presentations), TurboTax Online (tax preparation), and Windows Live Hotmail (e-mail).

Content Aggregator  A content aggregator is a business that gathers and organizes Web content and then distributes, or feeds, the content to subscribers for free or a fee. Examples of distributed content include news, music, video, and pictures. Subscribers select content in which they are interested. Whenever the selected content changes, it is downloaded automatically (pushed) to the subscriber's computer or mobile device.

 RSS 2.0, which stands for Really Simple Syndication, is a specification that some content aggregators use to distribute content to subscribers. Atom is another specification sometimes used by content aggregators to distribute. Some current browsers include a feature, such as Internet Explorer's WebSlices, that enables content aggregators to mark sections of their Web pages as feeds to which users can subscribe.

Personal  A private individual or family not usually associated with any organization may maintain a personal Web site or just a single Web page. People publish personal Web pages for a variety of reasons. Some are job hunting. Others simply want to share life experiences with the world.

Multimedia on the Web

 Most Web pages include more than just formatted text and links. The more exciting Web pages multimedia. Multimedia refers to any application that combines text with graphics, animation, audio, video, and/or virtual reality. Multimedia brings a Web page to life, increases the types of information available on the Web, expands the Web's potential uses, and makes the Internet a more entertaining place to explore. Multimedia Web pages often require specific hardware and software and take more time to download because they contain large graphics files and video or audio clips. Many Web sites have an option that allows visitors to disable multimedia, for example, if they have a slower-speed Internet connection.

 The sections that follow discuss how the Web uses graphics, animation, audio, video, and virtual reality.

Graphics  A graphic, or graphical image, is a digital representation of nontext information such as a drawing, chart, or photo. Today, many Web pages use colorful graphical designs and images to convey messages.

 The Web contains countless images about a variety of subjects. You can download many images of these images at not cost and use them for noncommercial purposes. Recall that downloading is the process of transferring an object from the Web to your computer. For example, you can insert images into greeting cards, announcements, and other documents.

 Of the graphics formats that exit on the Web, the two more common are JPEG and GIF formats. JPEG is a format that compresses graphics to reduce their file size, which means the file takes up less storage space. Smaller file sizes result in faster downloading of Web pages because small files transmit faster than large files. The more compressed the file, the smaller the image and the lower the quality. The goal with JPEG graphic is to reach a balance between image quality and file size. Digital photos often use the JPEG format.

 GIF graphics also use compression techniques to reduce file sizes. The GIF format works best for images that have only a few distinct colors, such as company logos. The newer PNG graphics format improves upon the GIF format, and thus may eventually replace the GIF format.

 The BMP and TIFF formats may require special viewer software, and they have larger file sizes. Thus, these formats are not used on the Web as frequently as JPEG, GIF and PNG formats.

 Some Web sites use thumbnails on their pages because graphics can be time-consuming to display. A thumbnail is a small version of a larger graphic. You usually can click a thumbnail to display a larger image.

Animation  Many Web pages use animation which is the appearance of motion created by displaying a series of still images in sequence. Animation can make Web pages more visually interesting or draw attention to important information or links. For example, text that animates by scrolling across the screen can serve as a ticker to display stock updates, news, sports scores, weather, or other information. Web-based games often use animation.

 Web page developers add animation to Web pages using a variety of techniques. Web page authoring programs, such as Adobe Flash and Microsoft Expression Web, enable Web site developers to combine animation and interactivity in Web pages. Developers unfamiliar with Web page authoring programs can create an animated GIF, which combines several GIF images in a single GIF file.

Audio  On the Web, you can listen to radio clips and live audio. Audio includes music, speech, or any other sound. Simple applications consist of individual audio files available for download to a computer or device. Once downloaded, you can play (listen to) the contents of these files. Some common Web audio file formats are: AAC, AIFF, ASF, MP3, Ogg, WAV, WMA, RA, QT. Audio files are compressed to reduce their file sizes. For example, the MP3 format reduces an audio file to about one-tenth its original size, while preserving much of the original quality of the sound.

 Some music publishers have Web sites that allow users to download sample tracks free to persuade them to buy all the songs contained on the CD. Others allow a user to purchase and download an entire CD. It is legal to download copyrighted music only if the song's copyright holder has granted permission for users to download and play the song.

 To listen to an audio file on your computer, you need special software called a player. Most current operating systems contain a player, for example, Windows Media Player. Some audio files, however, might require you to download a player. Players available for download include iTunes and RealPlayer. You can download the players free from the Web; some are plug-ins, which are discussed later.

 Some applications on the Web use streaming audio. Streaming is the process of transferring data in a continuous and even flow. Streaming allows users to access and use a file while it is transmitting. For example, streaming audio enables you to listen to music as it downloads to your computer. Many radio and television stations use streaming audio to broadcast music, interviews, talks shows, sporting events, music, video, news, live concerts, and other segments.

 Podcasting is another popular method of distributing audio. 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 such as an iPod. Examples of podcasts include music, radio shows, news stories, classroom lectures, political messages, and television commentaries. Podcasters register their podcasts with content aggregators. Subscribers select podcast feeds they want to be downloaded automatically whenever they connect. Most smart phone users who subscribe to a wireless Internet service provider can listen to streaming audio and podcasts.

Video  On the Web, you can view video clips or watch live video. Video consists of images displayed in motion. Most video also has accompanying audio. You can use the Internet to watch live and/or prerecorded coverage of your favorite television programs or enjoy a live performance of your favorite vocalist. You can upload, share, or view video clips at a video sharing Web site such as YouTube. Educators, politicians, and businesses are using video blogs and video podcasts to engage students, voters, and consumers.

 Simple video applications on the Web consist of individual video files, such as movie or television clips, that you must download completely before you can play them on the computer. Video files often are compressed because they are quite large in size. These clips also are short in length, usually less than 10 minutes, because they can take a long time to download. The Moving pictures Experts Group (MPEG) defines a popular video compression standard, a widely used one called MPEG-4 or MP4. Another popular video format is Adobe Flash.

 As with streaming audio, streaming video allows you to view longer or live video images as they download to your computer. Widely used standards supported by most Web browsers for transmitting streaming video data on the Internet are AVI (Audio Video Interleaved), QuickTime, Widows Media Format, and RealVideo. Like RealAudio, RealVideo is supported by RealPlayer.

Virtual Reality  Virtual reality (VR) is the use of computers to simulate a real or imagined environment that appears as a three-dimensional (3D) space. VR involves the display of 3-D images that users explore and manipulate interactively.

 Using special VR software, a Web developer creates an entire 3-D environment that contains infinite space and depth, called a VR world. A VR world, for example, might show a house for sale. Potential buyers walk through rooms in VR house by moving an input device forward, backward, or to the side.

 Games and simulations on optical disc or on the Web often use VR. Many practical applications of VR also exist. Science educators create VR modes of molecules, organisms, and other structures for students to examine. Companies use VR to showcase products or create advertisements. Architects create VR models of buildings and rooms so that clients can see how a completed construction project will look before it is built.

Plug-ins  Most Web browsers have the capability of displaying basic multimedia elements on a Web page. Sometimes, a browser might need an additional program, called a plug-in. A plug-in, or add-on, is a program that extends the capability of a browser. You can download many plug-in at no cost from various Web sites. Some plug-ins run on all sizes of personal computers and mobile devices. Others have special versions for mobile devices.            

Web Publishing

 Before the World Wide Web, the means to share opinions and ideas with others easily and inexpensively was limited to the media, classroom, work, or social environments. Generating an advertisement or publication that could reach a massive audience required much expense; today, businesses and individuals convey information to millions of people by creating their own Web pages. The content of the Web pages ranges from news stories to product information to blogs.

 Web publishing is the development and maintenance of Web pages. To develop a Web page, you do not have to be a computer programmer. For the small business or home user, Web publishing is fairly easy as long as you have the proper tools. 

 The five major steps in Web publishing are as follows:  

1. Plan a Web site.

Think about issues that could affect the design of the Web site. Identify the purpose of the Web site and the characteristics of the people whom you want to visit the Web site. Determine ways to differentiate your Web site from other similar ones.

2. Analyze and design a Web site.

Design the layout of elements of the Web site such as links, text, graphics, animation, audio, video, and virtual reality. Required hardware may include a digital camera, Web cam, scanner, sound card, and microphone.

3. Create a Web site.

Use word processing program to create basic Web pages that contain text and graphics. Use Web page authoring software to create more sophisticated Web sites that include text, graphics, animation, audio, video, and special effects. For advanced features such as managing users, passwords, chat rooms, and e-mail, you may need to purchase specialized Web site management software.

4. Deploy a Web site.

Transfer the Web pages from your computer to a Web server. Many Internet access providers offer their customers storage space on a Web server. Another option is a Web hosting service, which provides storage space on a Web server for a reasonable monthly fee. To help others locate your Web page, register your Web address with various search engines to ensure your site will appear in the hit lists for searches for certain keywords.

5. Maintain a Web site.

Visit the Web site regularly to ensure the Web site contents are current and all links work properly.