Discovering Computers Ch. 2

also called the Net, is a world-wide collection of networks that links millions of businesses, government agencies, educational institutions, and individuals.

The original ARPANET consisted of four main computers, one each located at the University of California at Los Angeles, the University of California at Santa Barbara, the Stanford Research Institute, and the University of Utah. of these computers served as a host on the network. A host, more commonly known today as a server, is any computer that provides services and connections to other computers on a network.

Oversees research and sets standards and guidelines for many areas of the Internet. The mission of the W3C is to contribute to the growth of the Web.

a not-for-profit research and development project that connects more than 200 universities and 115 companies via a high-speed pri- vate network. Founded in 1996, the goal of Internet2 is to develop and test advanced network technologies that will benefit Internet users in the short-term future.

provides high-speed Internet access through the cable television network via a cable modem.

provides high-speed Internet connections using regular copper telephone lines.

uses fiber-optic cable to provide high-speed Internet access to home and business users.

provides high-speed Internet connections using a dish-shaped antenna on your house or business to communicate with a tower location via radio signals.

offers high-speed Internet connections to devices with built-in compatible technology or computers with wireless modems.

network uses radio signals to provide high-speed Internet connections to compatible or properly equipped wireless computers and devices.

provides high-speed Internet connections via satellite to a satellite dish that communicates with a satellite modem.

An access provider is a business that provides individuals and organizations access to the Internet free or for a fee.

is a regional or national access provider. A regional ISP usually provides Internet access to a specific geographic area. A national ISP is a business that provides Internet access in cities and towns nation-wide

wireless Internet service provider, sometimes called a wireless data provider, is a company that provides wireless Internet access to desktop and notebook computers and mobile devices, such as smart phones and portable media players, with built-in wireless capability (such as Wi-Fi) or to computers using wireless modems or wireless access devices.

The major carriers of network traffic are known as collectively

short for Internet Protocol address, is a number that uniquely identifies each computer or device connected to the Internet.

the text version of an IP address.

is the method that the Internet uses to store domain names and their corresponding IP address

translates the domain name to its associated IP address so that data and information can be routed to the correct computer. A DNS server is an Internet server that usually is associated with an Internet access provider.

consists 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.

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).

is a computer that delivers requested Web pages to your computer. The same Web server can store multiple Web sites.

is a collection of related Web pages and associated items, such as documents and pictures, stored on a Web server.

or browser, is application software that allows users to access and view Web pages or access Web 2.0 programs.

refers to the first page that a Web site displays. Similar to a book cover or a table of contents for a Web site, the home page provides information about the Web site's purpose and content.

short for hyperlink, is a built-in connection to another related Web page or part of a Web page.

Downloading is the process of a computer or device receiving information, such as a Web page, from a server on the Internet.

A Web page has a unique address, called a URL (Uniform Resource Locator) or Web address.

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.

When you enter a Web address in a browser, you request, or pull, information

Some Web servers also can push content to your computer at regular intervals or whenever updates are made to the site.

refers to links in text-based documents

Combines text-based links with graphic, audio, and video links. Links allow you to obtain information in a nonlinear way.

where the top of the browser displays a tab (similar to a file folder tab) for each Web page you open

A search engine is a program that finds Web sites, Web pages, images, videos, news, maps, and other infor- mation related to a specific topic.

classifies Web pages in an organized set of categories, such as sports or shopping, and related subcategories.

that describes the item you want to find. Each word in the search text is known as a keyword.

Many search engines use a program called a spider to build and maintain 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.

A subject directory provides categorized lists of links arranged by subject

a Web site that offers a variety of Internet services from a single, convenient location (Figure 2-15a). 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.

is a Web site that joins a specific group of people with simi- lar interests or relationships. These com- munities may offer online photo albums, chat rooms, and other services to facilitate communications among members.

Web site contains newsworthy material including stories and articles relat- ing to current events, life, money, sports, and the weather

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.

contains content that promotes or sells products or services (Figure 2-15d). Nearly every enterprise has a business/marketing Web site

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.

refers to the activity of using links to explore the Web.

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 the general public.

An online social network, also called a social networking Web site, is a Web site that encourages members in its online community to share their interests, ideas, stories, photos, music, and videos with other registered users

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

An educational Web site offers exciting, challenging avenues for formal and infor- mal teaching and learning

An entertainment Web site offers an interactive and engaging environmentPopular 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

Web site that contains content that describes a cause, opinion, or idea. These Web sites usually present views of a particular group or association.

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: Google Docs

a business that gathers and organizes Web content and then distributes, or feeds, the content to sub- scribers 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.

which stands for Really Simple Syndication, is a specification that some con- tent aggregators use to distribute content to subscribers. Atom is another specification some- times used by content aggregators to distribute content. 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.

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.

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

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.

JPEG (pronounced JAY-peg) 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 graphics is to reach a balance between image quality and file size. Digital photos often use the JPEG format.

(pronounced jiff) 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. Simple diagrams, shapes, images with few colors. The newer PNG (pronounced ping) graphics format improves upon the GIF format, and thus may eventually replace the GIF format.

Desktop background, scanned images.

Web Graphics. The newer PNG (pronounced ping) graphics format improves upon the GIF format, and thus may eventually replace the GIF format.

Photos used by printing industry.

is a small version of a larger graphic. You usually can click a thumbnail to display a larger image.

On the Web, you can listen to audio clips and live audio. This 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.

Format that reduces an audio file to about one-tenth its original size, while still preserving much of the original quality of the sound. Moving Pictures Experts Group Audio Layer 3 (MPEG-3)

is the process of transferring data in a continuous and even flow. Allows users to access and use a file while it is transmitting. For example, ______ audio enables you to listen to music as it downloads to your computer.

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.

is the appearance of motion created by displaying a series of still images in sequence. It can make Web pages more visually interesting or draw attention to important information or links.

combines several GIF images in a single GIF file.

QT QuickTime audio, video, or 3-D animation

RA RealAudio sound file (supported by RealPlayer)

Windows media audio (part of windows media framework)

Windows waveform

Free, unpatented audio and video formats

Advanced streaming (or systems) format (part of windows media framework).

Audio Interchange File Format

Advanced Audio Coding

On the Web, you can view video clips or watch live video. They consist of images displayed in motion. Most video also has accompanying audio. Streaming video allows you to view longer or live video images as they download to your computer.

Virtual reality (VR) is the use of computers to simulate a real or imagined environment that appears as a three-dimensional (3-D) space. VR involves the display of 3-D images that users explore and manipulate interactively. Science educators create VR models of molecules, organisms, and other structures for students to examine.

or add-on, is a program that extends the capability of a browser. You can download many plug-ins 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 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.

E-commerce, short for electronic commerce, is a business transaction that occurs over an electronic network such as the Internet. Anyone with access to a computer or mobile device, an Internet connection, and a means to pay for purchased goods or services can participate in e-commerce. Some people use the term m-commerce (mobile commerce) to identify e-commerce that takes place using mobile devices.

Where a customer (consumer) visits an online business through. Which contains product descriptions, images, and a shopping cart.

Allows the customer to collect purchases.

Business-to-consumer (B2C) e-commerce consists of the sale of goods and services to the general public.

Consumer-to-consumer (C2C) e-commerce occurs when one consumer sells directly to another, such as in an online auction.

Users bid on an item being sold by someone else. The highest bidder at the end of the bidding period purchases the item. eBay is one of the more popular online auction Web sites. Example: eBay

Most e-commerce, though, actually takes place between businesses, which is called business-to-business (B2B) e-commerce. Businesses often provide goods and services to other businesses, such as online advertising, recruiting, credit, sales, market research, technical support, and training. For example, some MasterCard and Visa credit card companies provide corporations with Web-based purchasing, tracking, and transaction downloading capabilities.

(short for electronic mail ) is the transmission of messages and files via a computer network. E-mail was one of the original services on the Internet, enabling scientists and researchers working on government-sponsored projects to communicate with colleagues at other locations.

Use to create, send, receive, forward, store, print, and delete e-mail messages. Outlook and Windows Live Mail are two popular desktop e-mail programs; Gmail and Windows Live Hotmail are two popular free e-mail Web applications.

a combination of a user name and a domain name that identifies a user so that he or she can receive Internet e-mail

a unique combination of characters, such as letters of the alphabet and/or numbers, that identifies a specific user. Your user name must be different from the other user names in the same domain.

or contacts folder, which contains a list of names and e-mail addresses.

(simple mail transfer protocol) is a communications protocol used by some outgoing mail servers.

POP (Post Office Protocol), is a communications protocol used by some incoming mail servers.

the latest version of Post Office Protocol, is a communications protocol used by some incoming mail servers.

also called an e-mail list or distribution list, is a group of e-mail names and addresses given a single name. When a message is sent to a mailing list, every person on the list receives a copy of the message in his or her mailbox

To add your e-mail name and address to a mailing list, you subscribe to it.

To remove your name, you unsubscribe from the mailing list.

is a computer program that can damage files and the operating system. One way that virus authors attempt to spread a virus is by sending virus-infected e-mail attachments.

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 files or join a private chat room with them.

means that you and the people with whom you are conversing are online at the same time. Some IM services support voice and video con- versations

A chat is a real-time typed conversation that takes place on a computer. A chat room is a location on an Internet server that permits users to chat with each other. Anyone in the chat room can participate in the conversation, which usually is specific to a particular topic.

also called Internet telephony, enables users to speak to other users over the Internet. That is, VoIP uses the Internet (instead of the pub- lic switched telephone network) to connect a calling party to one or more local or long- distance called parties.

is an online area in which users have written discussions about a particular subject

A popular Web-based type of discussion group that does not require a newsreader is a message board. Many Web sites use message boards instead of newsgroups because they are easier to use.

is an Internet standard that permits file uploading and down- loading with other computers on the Internet.

is the opposite of downloading; that is the process of transferring documents, graphics, and other objects from your computer to a server on the Internet.

is a computer that allows users to upload and/or download files using FTP. An FTP site is a collection of files including text, graphics, audio clips, video clips, and program files that reside on an FTP server. Many FTP sites have anonymous FTP, whereby anyone can transfer some, if not all, available files. Some FTP sites restrict file transfers to those who have authorized accounts (user names and pass- words) on the FTP server.

which is short for Internet etiquette, is the code of acceptable behaviors users should follow while on the Internet; that is, it is the conduct expected of individuals while online. Netiquette includes rules for all aspects of the Internet, including the World Wide Web, e-mail, instant messaging, chat rooms, FTP, and newsgroups and message boards. Treat others as you would want to be treated.